Is there a pull request template that does this?

Edit: I was worried about possibly needing to change license. For now I will just use a permissive license. The situation is made seemingly complicated by the possible need to use copylefted images, combined with the possible need for using server code (which shouldn't use creative commons) in addition to the static html. I would rather deal with including parts with different licenses (probably not as complicated as I initially thought) instead of contributor license agreements.

Edit 2: Also, license enforcement is not very important for my project.

Edit 3: Now I'm using creative commons zero and making the repo comply with https://reuse.software/