Preferring to use the `general` package for defining leader-prefixed keybindings
than `evil-leader`.
This TODO has existed for quite awhile, so I'm pleased to finish it!
During the cleanup, I deleted some keybindings that I no longer used.
The things that I dislike about this setup are:
1. `xref-find-definitions` takes me to `/nix/store`, which is a read-only
version of the source code, so I cannot edit it, which doesn't feel lispy.
2. I need to rebuild the derivation when I change something, which also doesn't
feel lispy.
There are ways to circumvent both of these drawbacks, but for now, I'm checking
this in only to later revert it.
