Add Cheatsheet to docs generated by nathanlesage/cheatsheet-generator

[rodrigc]

I was playing with https://github.com/nathanlesage/cheatsheet-generator ,
and was able to generate a cheatsheet for Amethyst:

https://raw.githack.com/rodrigc/Amethyst/cheatsheet/docs/cheatsheet/Amethyst%20Keyboard%20Shortcuts.htm

Any interest in adding this to the Amethyst docs? No big deal if it doesn't meet the needs of Amethyst docs.
I thought I would just share it, because I thought it was kind of cool.

Do you know of any other cheatsheet generator programs out there?