Suggestion for Readme

[ehennestad]

Just found out that cloning this repo with the Github Desktop app cause some errors when trying to change branches due to github desktop not being compatible with submodules.

I suggest to add a few lines to the readme, that this repo should be cloned from the terminal, and not through e.g Github Desktop

[lzehl]

@apdavison @skoehnen OR @olinux could you please verify the issue? If this is indeed the case we should add the limitation as suggested by @ehennestad (thanks for bringing this to our attention)