Add xdg settings, cache, cleanup script

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/default.nix

@@ -12,6 +12,7 @@
     ./configs/nix-ld
     ./configs/git
     ./configs/gpg-agent
+    ./scripts/cleanup
   ];
 
   boot = {
@@ -63,8 +64,13 @@
   };
 
   nix = {
-    settings.experimental-features = [ "nix-command" "flakes" ];
+    settings = {
+      use-xdg-base-directories = true;
+      experimental-features = [ "nix-command" "flakes" ];
+    };
+
     gc.automatic = true;
+    optimise.automatic = true;
   };
 
   nixpkgs.config.allowUnfree = true;