modules, overlays, and packages have their own default.nix re-exporting
things instead of reading file paths. slightly improves declarativeness.
wine-osu is removed; we're just using nix-gaming (for now).
our custom packages will now have to be accessed via pkgs.me instead of
just pkgs. helps know where it came from
future goals: get rid of our overlays completely, or at least not make
it replace anything from nixpkgs
