docs(api.md): improve page.waitFor docs for the options object (#5021)

docs/api.md

@@ -1965,6 +1965,12 @@ This is a shortcut for [page.mainFrame().url()](#frameurl)
 #### page.waitFor(selectorOrFunctionOrTimeout[, options[, ...args]])
 - `selectorOrFunctionOrTimeout` <[string]|[number]|[function]> A [selector], predicate or timeout to wait for
 - `options` <[Object]> Optional waiting parameters
+  - `visible` <[boolean]> wait for element to be present in DOM and to be visible. Defaults to `false`.
+  - `timeout` <[number]> maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout. The default value can be changed by using the [page.setDefaultTimeout(timeout)](#pagesetdefaulttimeouttimeout) method.
+  - `hidden` <[boolean]> wait for element to not be found in the DOM or to be hidden. Defaults to `false`.
+  - `polling` <[string]|[number]> An interval at which the `pageFunction` is executed, defaults to `raf`. If `polling` is a number, then it is treated as an interval in milliseconds at which the function would be executed. If `polling` is a string, then it can be one of the following values:
+    - `raf` - to constantly execute `pageFunction` in `requestAnimationFrame` callback. This is the tightest polling mode which is suitable to observe styling changes.
+    - `mutation` - to execute `pageFunction` on every DOM mutation.
 - `...args` <...[Serializable]|[JSHandle]> Arguments to pass to  `pageFunction`
 - returns: <[Promise]<[JSHandle]>> Promise which resolves to a JSHandle of the success value
 

lib/Page.js

@@ -1108,7 +1108,7 @@ class Page extends EventEmitter {
 
   /**
    * @param {(string|number|Function)} selectorOrFunctionOrTimeout
-   * @param {!Object=} options
+   * @param {!{visible?: boolean, hidden?: boolean, timeout?: number, polling?: string|number}=} options
    * @param {!Array<*>} args
    * @return {!Promise<!Puppeteer.JSHandle>}
    */