Merge pull request facebook#2414 from benleiken/patch-1

Moved key requirement note into 'getting started'

Author: chenglou

docs/docs/10.1-animation.md

@@ -52,6 +52,9 @@ var TodoList = React.createClass({
  }
 });
 ```
+> Note:
+>
+> You must provide [the `key` attribute](/react/docs/multiple-components.html#dynamic-children) for all children of `ReactCSSTransitionGroup`, even if rendering a single item. This is how React will determine which children have entered, left, or stayed.
 
 In this component, when a new item is added to `ReactCSSTransitionGroup` it will get the `example-enter` CSS class and the `example-enter-active` CSS class added in the next tick. This is a convention based on the `transitionName` prop.
 
@@ -128,10 +131,6 @@ var ImageCarousel = React.createClass({
 });
 ```
 
-> Note:
->
-> You must provide [the `key` attribute](/react/docs/multiple-components.html#dynamic-children) for all children of `ReactCSSTransitionGroup`, even if rendering a single item. This is how React will determine which children have entered, left, or stayed.
-
 ### Disabling Animations
 
 You can disable animating `enter` or `leave` animations if you want. For example, sometimes you may want an `enter` animation and no `leave` animation, but `ReactCSSTransitionGroup` waits for an animation to complete before removing your DOM node. You can add `transitionEnter={false}` or `transitionLeave={false}` props to `ReactCSSTransitionGroup` to disable these animations.