little-lightning: nix settings

hosts/little-lightning/home.nix

@@ -5,6 +5,14 @@
     ../../home/modules
   ];
 
+  nix = {
+    package = pkgs.nix;
+    settings = {
+      auto-optimise-store = true;
+      experimental-features = [ "nix-command" "flakes" ];
+    };
+  };
+
   snowhawk = {
     alacritty.enable = true;
     macos.enable = true;