Add git stash abbreviations

[llakala]

Been planning on doing this for ages. I may as well make it an issue.

[bittner]

I see you're using fish (instead of zsh), hence suggesting OMZ and its git plugin the way I did it is probably not helpful.

It looks like there's an equivalent to OMZ, Oh My Fish, and there's also a git plugin for it. Maybe give it a shot?

This way you would go more standard, less home-grown. IMHO, that's generally a good idea.

[llakala]

I actually prefer doing these things home grown. If you take a peek at my abbreviations, they often end up specialized. Plus, doing them home-grown often teaches me about the underlying tools.