Clean up packages and export them as a nix flake

configuration.nix

flake.lock

flake.nix

layers/base.nix

layers/zsh.nix

pkgs/default.nix

pkgs/dotnet-sdk/default.nix

pkgs/gamescope/default.nix

pkgs/gamescope/release.nix

pkgs/haskell-ide-engine/all-hies.json

pkgs/haskell-ide-engine/default.nix

pkgs/haskell-ide-engine/update

pkgs/libliftoff/default.nix

pkgs/libliftoff/release.nix

pkgs/netevent/default.nix

pkgs/nginx-sso/default.nix