Continue moving out of the overlay model for everything and into running
sutff directly out of the packages. This should give a cleaner
separation of the things that I don't need to maintain separately
Renamed the @inputs to @top. This was a misguided attempt to make a
different change, but it's going to stick, now.
Began moving packages to their own folder rather than being intermingled
with overlays
Created a local overlay that just includes my personal packages
Cleaned up some dead code
Moved to just using the raw 'imports' instead of needing to explicitly
call out the `foo = import foo.nix {};` syntax