Update git-101.md

add link to http://justinhileman.info/article/git-pretty/ [skip ci]

docs/git-101.md

@@ -45,6 +45,10 @@ changes, and issue a pull request.
 [Githug](https://github.com/Gazler/githug) is a great gamefied way to learn git in couple hours.
 After finishing 50+ real-world scenarios you will have a pretty good idea about what and when you can do with git.
 
+## Cheatsheets
+
+#### Git pretty
+[So you have a mess on your hands?](http://justinhileman.info/article/git-pretty/)
 
 ## Scenarios