[FEATURE] Add support for Gogs/Gitea (especially Codeberg.org)

[kytta]

What / Why

There shall be support for Codeberg.org, a community-driven, non-profit software development platform. Since it's a public Gitea instance, which itself is a fork of Gogs, one could add support for the whole range of Git services.

When

• n/a

Where

• n/a

How

Current Behavior

• no support for Codeberg (or any Gitea/Gogs instance) is present

Expected Behavior

• there is support for Codeberg.org
• (optionally) there is also support for any self-hosted instance of Gitea and/or Gogs

Who

• n/a

References

• Related to #67

[hoijui]

By now, Codeberg.org uses ForgeJo, which is a fork of Gitea.