Credit new contributors

[stefanv]

The release notes generator we used previously generated credit for new contributors:

New Contributors

 • @some-person-name made their first contribution in #57

This would be nice to have!

[lagru]

Highlighting new contributors would indeed be very useful. GitHub already does this on the UI level so maybe there's a GraphQL or API way to query this property directly. Do you remember how the previous solution handled this problem?

Otherwise, the hard part is arriving at a complete set of all previous contributors to compare to. Just parsing the full history seems very expensive.

A performant but a bit annoying solution might be something like

• Add a --previous-contributors FILE option. It expects a simple CSV file (or similar) with ideally the databaseId of users. Login would work as well (and should be included), but might break down if users rename themselves.
• Add a --append-new-contributors FILE option which appends contributors which aren't already in the file.