home: x: add cursor

I would like to check out alternative themes. Notably Quintom [1],
Volantes [2], and Vimix [3].

[1]: https://gitlab.com/Burning_Cube/quintom-cursor-theme
[2]: https://github.com/varlesh/volantes-cursors
[3]: https://github.com/vinceliuice/Vimix-cursors

home/x/cursor.nix

@@ -0,0 +1,12 @@
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.my.home.x;
+in
+{
+  config = lib.mkIf cfg.enable {
+    xsession.pointerCursor = {
+      package = pkgs.numix-cursor-theme;
+      name = "Numix-Cursor";
+    };
+  };
+}

home/x/default.nix

@@ -4,6 +4,7 @@ let
 in
 {
   imports = [
+    ./cursor.nix
     ./keyboard.nix
   ];