Add note about enter/leave bubbling

Fixes #2826.

docs/docs/ref-05-events.md

@@ -117,6 +117,8 @@ onDragOver onDragStart onDrop onMouseDown onMouseEnter onMouseLeave
 onMouseMove onMouseOut onMouseOver onMouseUp
 ```
 
+The `onMouseEnter` and `onMouseLeave` events propagate from the component being left to the one being entered instead of ordinary bubbling and do not have a capture phase.
+
 Properties:
 
 ```javascript