docs: add the word the everywhere (#1988)

docs/api.md

@@ -237,14 +237,14 @@
 
 Puppeteer is a Node library which provides a high-level API to control Chromium or Chrome over the DevTools Protocol.
 
-Puppeteer API is hierarchical and mirrors browser structure. On the following diagram, faded entities are not currently represented in Puppeteer.
+The Puppeteer API is hierarchical and mirrors the browser structure. On the following diagram, faded entities are not currently represented in Puppeteer.
 
 ![puppeteer overview](https://user-images.githubusercontent.com/746130/31592143-089f6f9a-b1db-11e7-9a20-16b7fc754fa1.png)
 
-- [`Puppeteer`](#class-puppeteer) communicates with browser using [devtools protocol](https://chromedevtools.github.io/devtools-protocol/).
+- [`Puppeteer`](#class-puppeteer) communicates with the browser using [DevTools Protocol](https://chromedevtools.github.io/devtools-protocol/).
-- [`Browser`](#class-browser) instance owns multiple pages.
+- [`Browser`](#class-browser) instance can own multiple pages.
 - [`Page`](#class-page) has at least one frame: main frame. There might be other frames created by [iframe](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe) or [frame](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/frame) tags.
-- [`Frame`](#class-frame) has at least one execution context - default execution context - where frame's JavaScript is executed. Frame might have additional execution contexts associated with [extensions](https://developer.chrome.com/extensions).
+- [`Frame`](#class-frame) has at least one execution context - the default execution context - where the frame's JavaScript is executed. A Frame might have additional execution contexts that are associated with [extensions](https://developer.chrome.com/extensions).
 
 (Diagram source: [link](https://docs.google.com/drawings/d/1Q_AM6KYs9kbyLZF-Lpp5mtpAWth73Cq8IKCsWYgi8MM/edit?usp=sharing))
 
@@ -260,7 +260,7 @@ Puppeteer looks for certain [environment variables](https://en.wikipedia.org/wik
 ### class: Puppeteer
 
 Puppeteer module provides a method to launch a Chromium instance.
-The following is a typical example of using a Puppeteer to drive automation:
+The following is a typical example of using Puppeteer to drive automation:
 ```js
 const puppeteer = require('puppeteer');
 
@@ -298,18 +298,18 @@ This methods attaches Puppeteer to an existing Chromium instance.
 - `options` <[Object]>  Set of configurable options to set on the browser. Can have the following fields:
   - `ignoreHTTPSErrors` <[boolean]> Whether to ignore HTTPS errors during navigation. Defaults to `false`.
   - `headless` <[boolean]> Whether to run browser in [headless mode](https://developers.google.com/web/updates/2017/04/headless-chrome). Defaults to `true` unless the `devtools` option is `true`.
-  - `executablePath` <[string]> Path to a Chromium or Chrome executable to run instead of bundled Chromium. If `executablePath` is a relative path, then it is resolved relative to [current working directory](https://nodejs.org/api/process.html#process_process_cwd).
+  - `executablePath` <[string]> Path to a Chromium or Chrome executable to run instead of the bundled Chromium. If `executablePath` is a relative path, then it is resolved relative to [current working directory](https://nodejs.org/api/process.html#process_process_cwd).
   - `slowMo` <[number]> Slows down Puppeteer operations by the specified amount of milliseconds. Useful so that you can see what is going on.
-  - `args` <[Array]<[string]>> Additional arguments to pass to the browser instance. List of Chromium flags can be found [here](http://peter.sh/experiments/chromium-command-line-switches/).
+  - `args` <[Array]<[string]>> Additional arguments to pass to the browser instance. The list of Chromium flags can be found [here](http://peter.sh/experiments/chromium-command-line-switches/).
   - `ignoreDefaultArgs` <[boolean]> Do not use [`puppeteer.defaultArgs()`](#puppeteerdefaultargs). Dangerous option; use with care. Defaults to `false`.
-  - `handleSIGINT` <[boolean]> Close browser process on Ctrl-C. Defaults to `true`.
+  - `handleSIGINT` <[boolean]> Close the browser process on Ctrl-C. Defaults to `true`.
-  - `handleSIGTERM` <[boolean]> Close browser process on SIGTERM. Defaults to `true`.
+  - `handleSIGTERM` <[boolean]> Close the browser process on SIGTERM. Defaults to `true`.
-  - `handleSIGHUP` <[boolean]> Close browser process on SIGHUP. Defaults to `true`.
+  - `handleSIGHUP` <[boolean]> Close the browser process on SIGHUP. Defaults to `true`.
   - `timeout` <[number]> Maximum time in milliseconds to wait for the browser instance to start. Defaults to `30000` (30 seconds). Pass `0` to disable timeout.
-  - `dumpio` <[boolean]> Whether to pipe browser process stdout and stderr into `process.stdout` and `process.stderr`. Defaults to `false`.
+  - `dumpio` <[boolean]> Whether to pipe the browser process stdout and stderr into `process.stdout` and `process.stderr`. Defaults to `false`.
   - `userDataDir` <[string]> Path to a [User Data Directory](https://chromium.googlesource.com/chromium/src/+/master/docs/user_data_dir.md).
-  - `env` <[Object]> Specify environment variables that will be visible to browser. Defaults to `process.env`.
+  - `env` <[Object]> Specify environment variables that will be visible to the browser. Defaults to `process.env`.
-  - `devtools` <[boolean]> Whether to auto-open DevTools panel for each tab. If this option is `true`, the `headless` option will be set `false`.
+  - `devtools` <[boolean]> Whether to auto-open a DevTools panel for each tab. If this option is `true`, the `headless` option will be set `false`.
 - returns: <[Promise]<[Browser]>> Promise which resolves to browser instance.
 
 The method launches a browser instance with given arguments. The browser will be closed when the parent node.js process is closed.
@@ -330,7 +330,7 @@ BrowserFetcher can download and manage different versions of Chromium.
 BrowserFetcher operates on revision strings that specify a precise version of Chromium, e.g. `"533271"`. Revision strings can be obtained from [omahaproxy.appspot.com](http://omahaproxy.appspot.com/).
 
 Example on how to use BrowserFetcher to download a specific version of Chromium and run
-puppeteer against it:
+Puppeteer against it:
 
 ```js
 const browserFetcher = puppeteer.createBrowserFetcher();
@@ -414,9 +414,9 @@ puppeteer.launch().then(async browser => {
 });
 ```
 #### event: 'disconnected'
-Emitted when puppeteer gets disconnected from the Chromium instance. This might happen because one of the following:
+Emitted when Puppeteer gets disconnected from the Chromium instance. This might happen because of one of the following:
 - Chromium is closed or crashed
-- `browser.disconnect` method was called
+- The [`browser.disconnect`](#browserdisconnect) method was called
 
 #### event: 'targetchanged'
 - <[Target]>
@@ -436,11 +436,11 @@ Emitted when a target is destroyed, for example when a page is closed.
 #### browser.close()
 - returns: <[Promise]>
 
-Closes Chromium and all of its pages (if any were opened). The browser object itself is considered disposed and cannot be used anymore.
+Closes Chromium and all of its pages (if any were opened). The [Browser] object itself is considered to be disposed and cannot be used anymore.
 
 #### browser.disconnect()
 
-Disconnects Puppeteer from the browser, but leaves the Chromium process running. After calling `disconnect`, the browser object is considered disposed and cannot be used anymore.
+Disconnects Puppeteer from the browser, but leaves the Chromium process running. After calling `disconnect`, the [Browser] object is considered disposed and cannot be used anymore.
 
 #### browser.newPage()
 - returns: <[Promise]<[Page]>> Promise which resolves to a new [Page] object.
@@ -449,7 +449,7 @@ Disconnects Puppeteer from the browser, but leaves the Chromium process running.
 - returns: <[Promise]<[Array]<[Page]>>> Promise which resolves to an array of all open pages.
 
 #### browser.process()
-- returns: <?[ChildProcess]> Spawned browser process. Returns `null` if the browser instance was created with `puppeteer.connect` method.
+- returns: <?[ChildProcess]> Spawned browser process. Returns `null` if the browser instance was created with [`puppeteer.connect`](#puppeteerconnectoptions) method.
 
 #### browser.targets()
 - returns: <[Array]<[Target]>> An array of all active targets.
@@ -490,7 +490,7 @@ puppeteer.launch().then(async browser => {
 });
 ```
 
-The Page class emits various events (described below) which can be handled using any of Node's native EventEmitter methods, such as `on` or `once`.
+The Page class emits various events (described below) which can be handled using any of Node's native [`EventEmitter`](https://nodejs.org/api/events.html#events_class_eventemitter) methods, such as `on` or `once`.
 
 This example logs a message for a single page `load` event:
 ```js
@@ -644,7 +644,7 @@ Shortcut for [page.mainFrame().$x(expression)](#frameexpression)
 
 #### page.addScriptTag(options)
 - `options` <[Object]>
-  - `url` <[string]> Url of a script to be added.
+  - `url` <[string]> URL of a script to be added.
   - `path` <[string]> Path to the JavaScript file to be injected into frame. If `path` is a relative path, then it is resolved relative to [current working directory](https://nodejs.org/api/process.html#process_process_cwd).
   - `content` <[string]> Raw JavaScript content to be injected into frame.
 - returns: <[Promise]<[ElementHandle]>> which resolves to the added tag when the script's onload fires or when the script content was injected into frame.
@@ -655,7 +655,7 @@ Shortcut for [page.mainFrame().addScriptTag(options)](#frameaddscripttagoptions)
 
 #### page.addStyleTag(options)
 - `options` <[Object]>
-  - `url` <[string]> Url of the `<link>` tag.
+  - `url` <[string]> URL of the `<link>` tag.
   - `path` <[string]> Path to the CSS file to be injected into frame. If `path` is a relative path, then it is resolved relative to [current working directory](https://nodejs.org/api/process.html#process_process_cwd).
   - `content` <[string]> Raw CSS content to be injected into frame.
 - returns: <[Promise]<[ElementHandle]>> which resolves to the added tag when the stylesheet's onload fires or when the CSS content was injected into frame.
@@ -849,7 +849,7 @@ Adds a function which would be invoked in one of the following scenarios:
 - whenever the page is navigated
 - whenever the child frame is attached or navigated. In this case, the function is invoked in the context of the newly attached frame
 
-The function is invoked after the document was created but before any of its scripts were run. This is useful to amend JavaScript environment, e.g. to seed `Math.random`.
+The function is invoked after the document was created but before any of its scripts were run. This is useful to amend  the JavaScript environment, e.g. to seed `Math.random`.
 
 An example of overriding the navigator.languages property before the page loads:
 
@@ -1094,7 +1094,7 @@ The `format` options are:
 - `prototypeHandle` <[JSHandle]> A handle to the object prototype.
 - returns: <[Promise]<[JSHandle]>> Promise which resolves to a handle to an array of objects with this prototype.
 
-The method iterates JavaScript heap and finds all the objects with the given prototype.
+The method iterates the JavaScript heap and finds all the objects with the given prototype.
 
 ```js
 // Create a Map object
@@ -1345,7 +1345,7 @@ Shortcut for [page.mainFrame().waitForFunction(pageFunction[, options[, ...args]
 - returns: <[Promise]<[Response]>> Promise which resolves to the main resource response. In case of multiple redirects, the navigation will resolve with the response of the last redirect.
 
 #### page.waitForSelector(selector[, options])
-- `selector` <[string]> A [selector] of an element to wait for,
+- `selector` <[string]> A [selector] of an element to wait for
 - `options` <[Object]> Optional waiting parameters
   - `visible` <[boolean]> wait for element to be present in DOM and to be visible, i.e. to not have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
   - `hidden` <[boolean]> wait for element to not be found in the DOM or to be hidden, i.e. have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
@@ -1374,7 +1374,7 @@ puppeteer.launch().then(async browser => {
 Shortcut for [page.mainFrame().waitForSelector(selector[, options])](#framewaitforselectorselector-options).
 
 #### page.waitForXPath(xpath[, options])
-- `xpath` <[string]> A [xpath] of an element to wait for,
+- `xpath` <[string]> A [xpath] of an element to wait for
 - `options` <[Object]> Optional waiting parameters
   - `visible` <[boolean]> wait for element to be present in DOM and to be visible, i.e. to not have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
   - `hidden` <[boolean]> wait for element to not be found in the DOM or to be hidden, i.e. have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
@@ -1695,7 +1695,7 @@ The method evaluates the XPath expression.
 
 #### frame.addScriptTag(options)
 - `options` <[Object]>
-  - `url` <[string]> Url of a script to be added.
+  - `url` <[string]> URL of a script to be added.
   - `path` <[string]> Path to the JavaScript file to be injected into frame. If `path` is a relative path, then it is resolved relative to [current working directory](https://nodejs.org/api/process.html#process_process_cwd).
   - `content` <[string]> Raw JavaScript content to be injected into frame.
 - returns: <[Promise]<[ElementHandle]>> which resolves to the added tag when the script's onload fires or when the script content was injected into frame.
@@ -1704,7 +1704,7 @@ Adds a `<script>` tag into the page with the desired url or content.
 
 #### frame.addStyleTag(options)
 - `options` <[Object]>
-  - `url` <[string]> Url of the `<link>` tag.
+  - `url` <[string]> URL of the `<link>` tag.
   - `path` <[string]> Path to the CSS file to be injected into frame. If `path` is a relative path, then it is resolved relative to [current working directory](https://nodejs.org/api/process.html#process_process_cwd).
   - `content` <[string]> Raw CSS content to be injected into frame.
 - returns: <[Promise]<[ElementHandle]>> which resolves to the added tag when the stylesheet's onload fires or when the CSS content was injected into frame.
@@ -1915,7 +1915,7 @@ puppeteer.launch().then(async browser => {
 ```
 
 #### frame.waitForSelector(selector[, options])
-- `selector` <[string]> A [selector] of an element to wait for,
+- `selector` <[string]> A [selector] of an element to wait for
 - `options` <[Object]> Optional waiting parameters
   - `visible` <[boolean]> wait for element to be present in DOM and to be visible, i.e. to not have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
   - `hidden` <[boolean]> wait for element to not be found in the DOM or to be hidden, i.e. have `display: none` or `visibility: hidden` CSS properties. Defaults to `false`.
@@ -2037,7 +2037,7 @@ await resultHandle.dispose();
 - `prototypeHandle` <[JSHandle]> A handle to the object prototype.
 - returns: <[JSHandle]> A handle to an array of objects with this prototype
 
-The method iterates JavaScript heap and finds all the objects with the given prototype.
+The method iterates the JavaScript heap and finds all the objects with the given prototype.
 
 ```js
 // Create a Map object
@@ -2061,7 +2061,7 @@ const windowHandle = await page.evaluateHandle(() => window);
 // ...
 ```
 
-JSHandle prevents references JavaScript objects from garbage collection unless the handle is [disposed](#jshandledispose). JSHandles are auto-disposed when their origin frame gets navigated or the parent context gets destroyed.
+JSHandle prevents the referenced JavaScript object being garbage collected unless the handle is [disposed](#jshandledispose). JSHandles are auto-disposed when their origin frame gets navigated or the parent context gets destroyed.
 
 JSHandle instances can be used as arguments in [`page.$eval()`](#pageevalselector-pagefunction-args), [`page.evaluate()`](#pageevaluatepagefunction-args) and [`page.evaluateHandle`](#pageevaluatehandlepagefunction-args) methods.
 
@@ -2106,7 +2106,7 @@ Returns a JSON representation of the object. If the object has a
 [`toJSON`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#toJSON()_behavior)
 function, it **will not be called**.
 
-> **NOTE** The method will return an empty JSON if the referenced object is not stringifiable. It will throw an error if the object has circular references.
+> **NOTE** The method will return an empty JSON object if the referenced object is not stringifiable. It will throw an error if the object has circular references.
 
 ### class: ElementHandle
 
@@ -2477,7 +2477,7 @@ await client.send('Animation.setPlaybackRate', {
 #### cdpSession.detach()
 - returns: <[Promise]>
 
-Detaches session from target. Once detached, session won't emit any events and can't be used
+Detaches the cdpSession from the target. Once detached, the cdpSession object won't emit any events and can't be used
 to send messages.
 
 #### cdpSession.send(method[, params])
@@ -2546,7 +2546,7 @@ console.log(`Bytes used: ${usedBytes / totalBytes * 100}%`);
     - `start` <[number]> A start offset in text, inclusive
     - `end` <[number]> An end offset in text, exclusive
 
-> **NOTE** JavaScript Coverage doesn't include anonymous scripts; however, scripts with sourceURLs are
+> **NOTE** JavaScript Coverage doesn't include anonymous scripts. However, scripts with sourceURLs are
 reported.