update spriteCanvasMaterial doc

docs/examples/SpriteCanvasMaterial.html

@@ -23,6 +23,7 @@
 		parameters is an object that can be used to set up the default properties
 		</p>
 		<p>
+		rotation - the rotation of the sprite<br/>
 		color - the color of the sprite<br/>
 		program - the program used to draw the sprite
 		</p>
@@ -30,7 +31,10 @@
 
 		<h2>Properties</h2>
 
-
+		<h3>[property:Radians rotation]</h3>
+		<p>
+		The rotation of the sprite in radians. Default is 0.
+		</p>
 
 		<h3>[property:Color color]</h3>
 		<p>