Create contributors.md to recognize efforts of all contributors

[TeaganKing]

This is an alphabetized list of contributors to CUPiD. I'm open to other suggestions on order, organization, etc. Please note if you are expecting to see anyone else on this list; it will be shared with the team before being published.

• GitHub handles should be added

[TeaganKing]

Please update/add names as applicable! I'm going to send this PR out in our biweekly announcements as well in case anyone else wants to opt in.

I also added a note in our wiki contributors guide to help encourage people to add their names here when they contribute.

[mnlevy1981]

This list looks great! I have two questions before approving:

1. Should we update docs/conf.py to include this list on https://ncar.github.io/CUPiD/?
2. How should we handle contributors whose affiliation changes? The two that names that jump out as having recently left NCAR are @rmshkv and @ALDepp

[TeaganKing]

Thanks @mnlevy1981 , good points!

To do before merging:

• test github.io pages
• update Anna's affiliation

[TeaganKing]

The github.io page is rendering as expected! I'm going to commit one more minor change and then this should be ready for a final review, @mnlevy1981

[mnlevy1981]

This looks great, thanks @TeaganKing!