Starting to break out for different XPS systems

system/nix.nix

@@ -0,0 +1,12 @@
+{ config, pkgs, ... }:
+
+{
+  nix.settings.experimental-features = [ "nix-command" "flakes" ];
+  # This value determines the NixOS release from which the default
+  # settings for stateful data, like file locations and database versions
+  # on your system were taken. It's perfectly fine and recommended to leave
+  # this value at the release version of the first install of this system.
+  # Before changing this value read the documentation for this option
+  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
+  system.stateVersion = "25.05"; # Did you read the comment?
+}