Add "Only supports one child" to TouchableWithoutFeedback

Summary: Closes https://github.com/facebook/react-native/pull/4985

Reviewed By: svcscm

Differential Revision: D2794384

Pulled By: bestander

fb-gh-sync-id: 7332a83df635619d1d6bfacbf6e9c71af90179d9

Libraries/Components/Touchable/TouchableWithoutFeedback.js

@@ -29,6 +29,10 @@ var PRESS_RETENTION_OFFSET = {top: 20, left: 20, right: 20, bottom: 30};
  * Do not use unless you have a very good reason. All the elements that
  * respond to press should have a visual feedback when touched. This is
  * one of the primary reason a "web" app doesn't feel "native".
+ * 
+ * > **NOTE**: TouchableWithoutFeedback supports only one child
+ * >
+ * > If you wish to have several child components, wrap them in a View.
  */
 var TouchableWithoutFeedback = React.createClass({
   mixins: [TimerMixin, Touchable.Mixin],