Create CONTRIBUTING.md

Author: benjhar

CONTRIBUTING.md

@@ -0,0 +1,6 @@
+**The Contributing Guidelines are simple:**
+
+* Build on top of existing code if possible.
+* Use PEP8 formatting
+* Be descriptive in your Pull Request. Make sure we know *what* you've done and *why*.
+* Please consider using [these](https://github.com/atom/atom/blob/master/CONTRIBUTING.md#git-commit-messages) guidelines when commiting, along with :heavy_plus_sign: `:heavy_plus_sign:` when adding new functionality