Convert flake.nix layout to use flake-utils-plus

[Lehmanator]

gytis-ivaskevicius

• Desystematizes inputs
• Pass nixpkgs.config options to all nixpkgs channels
• Apply overlays to all nixpkgs channels
• Apply patches on a selected channel
• Provides a package for nix repl on steriods.
• Export all modules as attrset: i.e. {a = import ./a.nix; b = import ./b.nix; }
• Export all overlays from channels as namespaced attrset instantiated w/ their nixpkgs version.
• Export all packages from all overlays.
• Automatically generate flake registry from inputs.
• Automatically generate NIX_PATH from inputs.
• Automatically symlink inputs' flake contents to /etc/nix/inputs
• Import flakes inside directories of your flake inputs.
• Set hostDefaults:
  • system
  • channelName (of nixpkgs)
  • extraArgs (i.e. specialArgs of nixosSystem)
  • modules
  • output (flake output config goes to: i.e. nixosConfigurations/darwinConfigurations/homeConfigurations
  • builder (e.g. nixos.lib.nixosSystem)