Add contributing guidelines

[pcgilday]

Since we are adding functionality as we need it, this module should detail contributing guidelines. We want to encourage anyone that finds this module/lib to open issues or add the functionality they may need.

TODO

• Add contributing guidelines that are helpful and clear.

Resources:

https://help.github.com/articles/setting-guidelines-for-repository-contributors/
http://contributor-covenant.org/

Acceptance Criteria

As a dev looking to contribute, I can see contributing guidelines that clearly detail out how to help out.