* chore: Use devtools-protocol package
Rather than maintain our own protocol we can instead use the devtools-protocol package and pin it to the version of Chromium that Puppeteer is shipping with.
The only changes are naming changes between the bespoke protocol that Puppeteer created and the devtools-protocol one.
* chore(docs): migrate & document all Page events
Rather than a generic `Events.ts` file we can instead document events as
an enum within each individual class. It's easier to document and work
with, and it's clearer where events originate from.
* chore(docs): reduce warnings when generating docs
This is a bunch of small miscellaneous fixes that reduce the amount of
warnings logged when generating our new docs. The long term goal is to
get this list down to 0 warnings, but I'll do it in multiple PRs.
* satisfy doclint
These files will be used by both the web and node versions of Puppeteer.
Another name for this might be "core" but I don't want to cause
confusion with the puppeteer-core package that we publish at the moment.
