Add full gitea support

[6543]

since it's original a gogs fork, we can utilize gogs code and improve it (#18)

gitea's api should cover all needs unresolved as for gogs
-> https://try.gitea.io/api/swagger

[guyzmo]

Hey 👋 gitea was originally supported back in '17.

But I had a lot going on in my life, and it's been some time I couldn't maintain all the APIs. Of course if you do a PR, I'd be happy to merge! 😉