Automatic of site update via GitHub Actions

[ilya-lavrenov]

Could you please automate site update with GitHub Actions?

Current readme does not even show how to run that rebuild.sh script.

[BillyONeal]

Unfortunately Actions are forbidden from editing code in Microsoft-controlled repos. We WANT this but have been unable to do so.

[ilya-lavrenov]

Github actions can submit PRs which can be reviewed by humans.