zh doc: restore the wrongly removed attribute in Audio.html

docs/api/zh/audio/Audio.html

@@ -75,6 +75,12 @@
 		<p>是否可以使用 [page:Audio.play play](),
 			[page:Audio.pause pause]()等方法控制播放. 默认为 *true*.</p>
 
+		<h3>[property:Boolean isPlaying]</h3>	
+		<p>是否正在播放</p>	
+
+		<h3>[property:AudioListener listener]</h3>	
+		<p>A reference to the listener object of this audio.</p>
+
 		<h3>[property:Number playbackRate]</h3>
 		<p>播放速率. 默认为 *1*.</p>