Support browserless (browser over websocket)

[cuthulino]

Hey,

from browserless there are docker containers, serving a remote ws for browser interaction.
It would be great to have a flag to use these instead of download a browser to local drive.

They got an example for puppeteer and it does look easy to use:

const browser = await puppeteer.connect({
  browserWSEndpoint: 'ws://localhost:3000',
});