Reorganize the repo for re-usability

[helmturner]

@zenlex I kinda forgot we made a separate branch for each solution. How do we reorganize in a way that makes sense?

Maybe the easiest solution is just renaming each branch with a common prefix such that they're sorted together (e.g. 2023, 2023-solved-compose, etc.) I think moving forward we should organize with directories, but this workaround gets us away from hack-y merge shenanigans.

I think we briefly tossed around the idea of making each year a separate branch, but I'm rethinking that a bit in favor of a more 'normal' trunk-based approach. With multiple co-organizers working from the same repo simultaneously, this would feel more familiar.

Maybe we could work on 'this year' from the root, and move it to an year-stamped subfolder for the next go-around?

Happy to shuffle things around if we're all cool with that.

Unrelated, do we have Nile and Crystal added to the org? I'm not seeing them come up when I @, but I don't know their GitHub handles either.