Design a way for people to contribute with metadata on the repos indexed

[Pierre-VF]

We're currently not linking much more than the URL of projects. It might be good to allow for metadata addition.

Several possibilities (and not necessarily an either/or):

1. Github-based process for users to contribute metadata directly in the repo
2. Other process for manual submission
3. API-based process for metadata submission (which automated systems also could use), with authentication at point of submission so that there is a way to identify who/what contributed.