Add CONTRIBUTING.md

[kinow]

Hi,

At the end of the README file there's some information for contributors, but perhaps this could be expanded to provide users with a clear and simple way to contribute. It should include what contributions are welcome (as is in the README file), how to build and what to build Carnival, if tests are expected, what type of test, any community guidelines (CLA, policies, etc), and anything else that might be helpful to contributors.

This is related to the JOSS paper review item:

Community guidelines: Are there clear guidelines for third parties wishing to 1) Contribute to the software 2) Report issues or problems with the software 3) Seek support

[hjwilli]

Hi @kinow, CONTRIBUTIONS.md has been added, please let us know if this is sufficient.

[kinow]

Hi @kinow, CONTRIBUTIONS.md has been added, please let us know if this is sufficient.

Yes! Thank you @hjwilli ! Closing.