GitHub to Gitea repo mirrors

[martinohmann]

I'd like to automatically mirror all my non-fork repos from GitHub to Gitea which is then backed up via volsync.

Some options:

• Terraform module: requires to run apply when I add a new repo on GitHub, which I'll probably forget.
• Argo Workflow: could regularily invoke a to-be-created script that install mirrors for all repos that don't have one already.