Add licensing information to Reproducibility guidelines

[seedscape]

Choose a license for source code: https://choosealicense.com

[ESodja]

This one may require a bit more research, I've never done anything with licensing before. I will look into it more.

[ESodja]

I took a look at Ethan White's github page (https://github.com/weecology) and it looks like most of his projects are under MIT license or CCO-1.0. I am not sure what the advantages or disadvantages are to each, but I will keep looking into them. #IAmNotALawyer