Community Recipes

[cdanwards]

After receiving some community contributions, we decided to update the license of the project, which will apply to the community contributors.

This PR:

• adds the information about the Creative Commons license
• updates the Contributing document as well adding a new pull request template pointing to the contributing page
• adds a separate Community Recipes section to the Cookbook as well as renaming the other section to Infinite Red Recipes

[jamonholmgren]

lgtm!

[lindboe]

Whoops, chose the wrong review status, but I do think we should clarify the license question