desktop updates

modules/home-manager/picom.nix

@@ -0,0 +1,16 @@
+{ pkgs, ... }:
+
+{
+  home.packages = [ pkgs.picom ];
+
+  xdg.configFile."picom/picom.conf".text = ''
+    backend = "glx";
+    vsync = true;
+
+    unredir-if-possible = false;
+
+    shadow = false;
+    fade-in-step = 1;
+    fade-out-step = 1;
+  '';
+}