cheat sheet should reference itself / its source

[dirks]

It would be nice if the cheat sheet would reference its online version or its source to always have a link to the up to date version.

This is especially true for printouts. Image people would get this during a course and stick it next to their screen. After the course they pick up on git again and suddenly a command does not work anymore! Might be git changed or there was an error in the old cheat sheet version. Instead of getting frustrated on this stupid git software they now check the fixed updated version and become happy git users.