[Feature] Add Firefox and Webkit dependencies to troubleshooting guide

[Tyriar]

When the browser fails to launch you get redirected here:

https://github.com/Microsoft/playwright/blob/master/docs/troubleshooting.md

After some looking around I found https://github.com/microsoft/playwright/blob/master/.github/workflows/tests.yml that contains some dependencies on how to run firefox and webkit. I only managed to get firefox running on Azure Pipelines though, webkit still failed when I installed these packages:

playwright/.github/workflows/tests.yml

Lines 84 to 88 in e658978

	- name: install required packages
	run: |
	sudo apt-get update
	sudo apt-get install libwoff1 libopus0 libwebp6 libwebpdemux2 libenchant1c2a libgudev-1.0-0 libsecret-1-0 libhyphen0 libgdk-pixbuf2.0-0 libegl1 libgles2 libevent-2.1-6 libnotify4 libxslt1.1
	sudo apt-get install xvfb

You can see the steps I went through in this PR: xtermjs/xterm.js#2722

[arjunattam]

Thanks for the suggestion @Tyriar, we should definitely add this. For now you could use this list. I've verified it to work for the 3 browsers, for Ubuntu 18.04 and Playwright 0.11.1.

[Tyriar]

Hm, that didn't seem to work 😕

xtermjs/xterm.js#2725
https://dev.azure.com/xtermjs/xterm.js/_build/results?buildId=3063&view=logs&j=a5202df1-cd2a-5288-9447-1453cf8875c8&t=5fc218d6-0ed8-555d-8192-8ac67e3288b5

[arjunattam]

Taking a look at it! Any chance we could add { dumpio: true } to the browser launch method? That will report the missing dependencies.

[Tyriar]

@arjun27 thanks, figured it out with dumpio (invalid browser args). That should definitely be mentioned in troubleshooting too. Created #1051 which I recommend doing across the public API to make the lib nicer to user.