Borrowing ideas from (in no particular order):
- https://github.com/glguy/advent2019
- https://github.com/mstksg/advent-of-code-2019
- https://github.com/mgkoning/advent-of-code-2019
- https://github.com/ephemient/aoc2019
- https://github.com/neilparikh/advent-of-code2019
- https://git.monade.li/aoc/tree/src
... and no doubt others. Thanks for the education guys.