Looking for a Git Tutorial Repository

There are already a few threads over here concerning git learning resources (e.g. Git tutorial / introduction to students)
However, I could not find a repository based one, which seem to be a natural fit for this community - so students can learn git while using git (through github classroom)!

I converted the gitimmersion.com exercise into a github repository (https://github.com/jce-il/git-immersion), but this one goes a little too deep for my students and is also somewhat outdated.

Any links? recommendations? suggestions?
Thanks in advance, Reuven