Gitea support

**Is your feature request related to a problem? Please describe.**

As a developer, I would like to use this package for my gitea projects.

**Describe the solution you'd like**

Basically the same features provided for GitHub where it's applicable.

**Describe alternatives you've considered**

There's almost no alternative which is independent and as feature-rich as intuit/auto...
For Golang projects it's possible to use goreleaser, maybe also for non go projects (I did not try), but I would rather use one tool than multiple different ones.
Especially none supports gitea.

**Additional context**

No additional context, just thanks for your work and that it would be amazing to have this for other git hosting providers aswell.