Added definitions to MMD cheat sheet

I wanted to contribute something I had put together for the mmd human readable guide. Hopefully, people will use it.
Merge pull request #12 from mandaris/master

This is my first pull request in a loooong time.
Alternative Vim cheat sheet
Merge branch 'master' of github.com:ttscoff/cheaters

* 'master' of github.com:ttscoff/cheaters:
  Added definitions to MMD cheat sheet
  Adding the restructuredText cheatsheet.
  Add regex cheat sheet from Patterns App
  Replaced image based TowerGit with HTML version
  Added a cheat sheet for Trickster.
Merge branch 'master' of https://github.com/ttscoff/cheaters

* 'master' of https://github.com/ttscoff/cheaters:
  Alternative Vim cheat sheet
  Added definitions to MMD cheat sheet