Attempt at using lix

Without remote builds and with my laptop setup it's not really viable
for now :(

os/default.nix

@@ -12,6 +12,7 @@
     ./diff
     ./gaming
     ./geoffrey.nix
+    # ./lix
     ./printing
     ./remote-builds
     ./style

os/lix/default.nix

@@ -0,0 +1,16 @@
+{ pkgs, lib, config, lix-module, ... }:
+{
+  imports = [
+    lix-module.nixosModules.default
+  ];
+  config = {
+    nix.settings = {
+      substituters = [
+        "https://cache.lix.systems"
+      ];
+      trusted-public-keys = [
+        "cache.lix.systems:aBnZUw8zA7H35Cz2RyKFVs3H4PlGTLawyY5KRbvJR8o="
+      ];
+    };
+  };
+}