Add Contributing Guide
Include 'issues' section
AUI-965 - Fix Form Validator checks for select elements
AUI-965 - Add unit tests
AUI-965 Source formatting
AUI-963 - Add documentation to ACE AutoComplete
AUI-963 - Add tests to AutoCompelte for Freemarker
AUI-963 - Add tests to AutoCompelte for Velocity
AUI-961 - Provide documentation to AUI Palette widget
AUI-961 - AUI Palette Unit tests
AUI-961 - Fix typo