Need OAuth documentation

[thebaer]

We don't currently have any documentation for setting up OAuth providers: Write.as, Slack, GitLab.

[thebaer]

Continuing from writefreely/writefreely#320, @idelem which provider are you trying to set up? Slack or GitLab?

[idelem]

Thanks for moving this issue. I was trying to set up Gitlab OAuth.

[ajhalili2006]

Since the modern SIWS uses OIDC instead of plain OAuth 2, is it possible to also implement OpenID Connect-related stuff to generic OAuth config or not?

[bsncubed]

Seconded. It would be crate to have OpenID Connect available for generic OAuth to connect Authelia.