Add Contributing Guide

[lrljoe]

Add start of Contributing Guide

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

New Feature Submissions:

1. Does your submission pass tests and did you add any new tests needed for your feature?
2. Did you update all templates (if applicable)?
3. Did you add the relevant documentation (if applicable)?
4. Did you test locally to make sure your feature works as intended?

Changes to Core Features:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?
• Have you successfully ran tests with your changes locally?

[codecov]

Codecov Report

Merging #1540 (52f7352) into develop (435f5c4) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             develop    #1540   +/-   ##
==========================================
  Coverage      88.98%   88.98%           
  Complexity      1264     1264           
==========================================
  Files             96       96           
  Lines           2997     2997           
==========================================
  Hits            2667     2667           
  Misses           330      330