Update packaging and CI config for CJ9

Unfortunately installing isort from source errors out due to a poetry
bug(?). Since isort 5.x has a stability policy active, let's just bump
this so the template is usable (and upgrade the template properly
later).

The screenshot is my own as I couldn't find a GitHub provided one that works unfortunately. Admittedly ugly.

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

…pletion

Various bug fixes and cleaned up the UI. Also added code documentation
ahead of the deadline.

Co-authored-by: thijsfranck <thijsfranck@gmail.com>

Co-authored-by: papaya <71032999+esmaycat@users.noreply.github.com>

git-subtree-dir: cool-cacti
git-subtree-mainline: 49c1216
git-subtree-split: 6e8dfa6

…053260'

git-subtree-dir: calm-calatheas
git-subtree-mainline: 05d0eb9
git-subtree-split: b65184a