Shake effect: Both is not a valid value. Fixes jquery#128.

Author: scottgonzalez

entries/shake-effect.xml

@@ -3,8 +3,8 @@
 	<title>Shake Effect</title>
 	<desc>Shakes the element multiple times, vertically or horizontally.</desc>
 	<arguments>
-		<argument name="direction" type="String" default='"both"'>
-			<desc>The direction of the effect. Possible values: <code>"left"</code>, <code>"right"</code>, <code>"up"</code>, <code>"down"</code>.</desc>
+		<argument name="direction" type="String" default='"left"'>
+			<desc>A value of <code>"left"</code> or <code>"right"</code> will shake the element horizontally, and a value of <code>"up"</code> or <code>"down"</code> will shake the element vertically. The value specifies which direction the element should move along the axis for the first step of the effect.</desc>
 		</argument>
 		<argument name="distance" type="Number" default="20">
 			<desc>Distance to shake.</desc>