organisation + move config for all devices to 'global' counterparts

modules/nh.nix

@@ -0,0 +1,15 @@
+{
+  inputs,
+  pkgs,
+  ...
+}: {
+  environment.systemPackages = with pkgs; [
+    inputs.nh.packages.${system}.default
+  ];
+  programs.nh = {
+    enable = true;
+    clean.enable = true;
+    clean.extraArgs = "--keep-since 3d --keep 3";
+    flake = "/home/grey/nixos";
+  };
+}