Show a warning for repositories that cloned the entire framework

[jwgmeligmeyling]

[TimvdLippe]

This is very specific to a course, so it might need additional work to make this modular for more courses. The best (but very long) version would be to create a framework where courses can create warnings. However this will become extremely complicated, so maybe there just ain't a clean and easy way to do this.

[jwgmeligmeyling]

I think #144 will already mark these groups.