Added ghosting info to Keyboard docs.

Author: photonstorm

README.md

@@ -93,6 +93,7 @@ Version 2.0.4 - "Mos Shirare" - in development
 * StateManager.restart incorrectly skipped the first additional parameter after clearCache (thanks @mariusbrn, fix #722)
 * Line.angle and Math.angleBetween used Math.atan2 arguments in the wrong order (thanks @jotson, fix #724)
 * Group.destroy checks parent before removing (thanks @clark-stevenson, fix #733)
+* Fixed typo in P2.World.setMaterial (thanks @OpherV, fix #739)
 
 
 ### ToDo

src/input/Keyboard.js

@@ -5,7 +5,10 @@
 */
 
 /**
-* The Keyboard class handles looking after keyboard input for your game. It will recognise and respond to key presses and dispatch the required events.
+* The Keyboard class handles looking after keyboard input for your game.
+* It will recognise and respond to key presses and dispatch the required events.
+* Please be aware that lots of keyboards are unable to process certain combinations of keys due to hardware
+* limitations known as ghosting. Full details here: http://www.html5gamedevs.com/topic/4876-impossible-to-use-more-than-2-keyboard-input-buttons-at-the-same-time/
 *
 * @class Phaser.Keyboard
 * @constructor