Add Gitea configuration in jx-requirements.yaml

[nbon12]

I couldn't find gitea in the list of supported git providers: https://jenkins-x.io/v3/admin/setup/config/git/ Is gitea supported? If so, what is the proper yaml configuration to use for gitea in the jx-requirements.yaml?

For example:

cluster:
  provider: ?
  gitKind: ?
...