Good first tasks

It might be a bit unclear how to contribute to a new and still-evolving project. Here are some ideas; if any of these sound like something you're interested in, feel free to open a dedicated issue where we can discuss implementation.

You may also want to skim through the Parking Lot and see if anything there catches your eye. (Some tasks from #6 are listed here as well. Some items in #6 are vague, conceptual, or not necessarily good ideas; every task here should be concrete and welcome.)