Add a help slide about WIP commits after git stash

[theFeu]

Git stash is a bit of a volatile command imho, so I would like to advise new learners of git to use WIP commits and then soft reset them in case git suggests a stash (at least until they are fully comfortable with git).

I personally and a bunch of git users I talked to try to avoid stash still, so code is less likely to be lost.

Opinions??