refactor config with better structure

nixos/hardware/bluetooth.nix

@@ -0,0 +1,12 @@
+{ ... }:
+{
+  hardware.bluetooth = {
+    enable = true;
+    settings = {
+      General = {
+        Experimental = true;
+      };
+    };
+  };
+  services.blueman.enable = true;
+}