Fix broken link in animation docs

Missed in facebook#2068

Author: zpao

docs/docs/09.1-animation.md

@@ -85,7 +85,7 @@ You'll notice that when you try to remove an item `ReactCSSTransitionGroup` keep
 
 ### Animation Group Must Be Mounted To Work
 
-In order for it to apply transitions to its children, the `ReactCSSTransitionGroup` must already be mounted in the DOM. The example below would not work, because the `ReactCSSTransitionGroup` is being mounted along with the new item, instead of the new item being mounted within it. Compare this to the [Getting Started](/docs/docs/09.1-animation.md#getting-started) section above to see the difference.
+In order for it to apply transitions to its children, the `ReactCSSTransitionGroup` must already be mounted in the DOM. The example below would not work, because the `ReactCSSTransitionGroup` is being mounted along with the new item, instead of the new item being mounted within it. Compare this to the [Getting Started](#getting-started) section above to see the difference.
 
 ```javascript{12-14}
  render: function() {