Including VGA example in 'xrandr' tutorial

tutorial/i3wm_screens.org

@@ -31,6 +31,12 @@ Running ~xrandr~ with the following arguments will put the output (let's call it
   xrandr --output HDMI --auto --left-of LVDS1
 #+end_example sh
 
+Using VGA instead of HDMI:
+
+#+begin_example sh
+  xrandr --output VGA1 --auto --left-of LVDS1
+#+end_example sh
+
 That's all! 
 
 You are good to use the new screen in a second workspace. Check the i3-wm userguide for more information.