Added garbage collection/storage optimization

configuration.nix

@@ -15,8 +15,21 @@ in
     ];
 
   # Bootloader.
-  boot.loader.systemd-boot.enable = true;
+  boot.loader.systemd-boot = {
+    enable = true;
+	configurationLimit = 10;
+  };
   boot.loader.efi.canTouchEfiVariables = true;
+
+  # Garbage collection
+  nix.gc = {
+    automatic = true;
+	dates = "weekly";
+	options = "--delete-older-than 1w";
+  };
+
+  # Optimize store
+  nix.settings.auto-optimise-store = true;
   
   # Use latest stable kernel
   boot.kernelPackages = pkgs.linuxPackages_latest;