Setup gh actions

[himorin]

I've checked

• output from HEAD of PR 492 and index.html in gh-pages is the same, except for syntax used by bikeshed
• configured to use main branch as a source, and gh-pages as a destination

and propose:

• remove index.html in gh-pages (done in this PR), to prevent local and/or remote crash

If fine, please (or I can take actions):

• switch source of github page to gh-pages (from main)
• merge this PR first
• merge PR Editorial: Align with Web IDL specification #492 second, and check all working

[gkatsev]

Should we include index.html in .gitignore so that it won't get checked in by people into the repo? We'd want to exclude .gitignore from the deploy copy as well.

Otherwise, this LGTM. Thanks @himorin!

[w3cbot]

himorin marked as non substantive for IPR from ash-nazg.

[himorin]

Should we include index.html in .gitignore so that it won't get checked in by people into the repo? We'd want to exclude .gitignore from the deploy copy as well.

updated.
(/html5/ in .gitignore should be removed??)

[himorin]

@gkatsev Let me propose as follows:

• merge this Setup gh actions #494 first (should work incl. GHActions)
• change github pages source to gh-pages branch
• cleaning up files in gh-pages branch, since we now have the same for main and gh-pages
• merge other PRs

[gkatsev]

@himorin that sounds great to me!

[gkatsev]

@himorin looks like the action failed :( https://github.com/w3c/webvtt/runs/1984601204#step:5:80

[gkatsev]

Actually, looks like it succeeded but then the rest of the action had an issue? 34e1ab9

[himorin]

Ah! I forgot recent update... (which I did for other WG)
let me open another PR.