configure mouse speed

system/desktop/x11.nix

@@ -9,5 +9,16 @@
 
   system.custom.fonts.enable = true;
 
+  # xinput list < to show devices
+  # https://unix.stackexchange.com/questions/90572/how-can-i-set-mouse-sensitivity-not-just-mouse-acceleration
+  services.xserver.displayManager.sessionCommands = let
+    mouseSpeed = name: speed: ''
+      ${pkgs.xlibs.xinput}/bin/xinput set-prop "${name}" "Coordinate Transformation Matrix" ${
+        toString speed
+      } 0 0 0 ${toString speed} 0 0 0 1 || true
+    '';
+  in lib.concatStringsSep "\n"
+  [ (mouseSpeed "Logitech Gaming Mouse G400" 3.1) ];
+
 }