Add XDG_DESKTOP_DIR to avoid Desktop/ being created

modules/x11.nix

@@ -9,6 +9,7 @@
 
   environment = {
     variables = {
+      XDG_DESKTOP_DIR = "$HOME/";
       XDG_CACHE_HOME = "$HOME/.cache";
       XDG_CONFIG_HOME = "$HOME/.config";
       XDG_DATA_HOME = "$HOME/.local/share";