Marked width/height as readonly and added docs. Fix #4806
Marked width/height as readonly and added docs. Fix #4806

BeanSeed/phaser,BeanSeed/phaser,TukekeSoft/phaser,photonstorm/phaser,spayton/phaser,photonstorm/phaser,TukekeSoft/phaser,spayton/phaser,TukekeSoft/phaser