Example flake.nix

Here is basic flake.nix

In the nixosConfigurations you should change ```'nixos'```` to be the host name for your system. If you dont do this you will need to specifiy the name you pick when using the nixos command to start using the flake.

{
  description = "Test Flake";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
  };

  outputs = { self, nixpkgs}:
    let
      lib = nixpkgs.lib;
    in {
      nixosConfigurations = {
        nixos = nixpkgs.lib.nixosSystem {
          system = "x86_64-linux";
          modules = [ ./configuration.nix ];
      };
    };
  };
}