Replace React.render() with ReactDOM.render() in doc
Replace React.render() with ReactDOM.render() in doc

Summary:
`React.render()` has been removed in favor of `ReactDOM.render()` in React 0.14.
Closes https://github.com/facebook/flow/pull/2157

Differential Revision: D3657319

Pulled By: jeffmo

fbshipit-source-id: 650a26afe2f284583e2778a4a6fd89156d72ae84

gabelevi/flow,gabelevi/flow,JonathanUsername/flow,gabro/flow,facebook/flow,popham/flow,nmote/flow,claudiopro/flow,jamesgpearce/flow,ForbesLindesay/flow,jgrund/flow,TiddoLangerak/flow,popham/flow,AgentME/flow,jamesgpearce/flow,gabro/flow,samwgoldman/flow,ylu1317/flow,AprilArcus/flow,MichaelDeBoey/flow,popham/flow,ylu1317/flow,facebook/flow,chenglou/flow,jeffmo/flow,chenglou/flow,AprilArcus/flow,jgrund/flow,gabelevi/flow,JonathanUsername/flow,ylu1317/flow,TiddoLangerak/flow,popham/flow,chenglou/flow,AprilArcus/flow,gabro/flow,fletcherw/flow,jgrund/flow,JonathanUsername/flow,fletcherw/flow,chenglou/flow,gabro/flow,fletcherw/flow,ForbesLindesay/flow,jamesgpearce/flow,gabelevi/flow,samwgoldman/flow,popham/flow,ForbesLindesay/flow,claudiopro/flow,TiddoLangerak/flow,JonathanUsername/flow,AprilArcus/flow,jeffmo/flow,jgrund/flow,samwgoldman/flow,fletcherw/flow,samwgoldman/flow,gabelevi/flow,TiddoLangerak/flow,ForbesLindesay/flow,jamesgpearce/flow,facebook/flow,MichaelDeBoey/flow,claudiopro/flow,mroch/flow,samwgoldman/flow,AprilArcus/flow,chenglou/flow,mroch/flow,gabro/flow,jeffmo/flow,MichaelDeBoey/flow,facebook/flow,nmote/flow,popham/flow,JonathanUsername/flow,MichaelDeBoey/flow,jgrund/flow,AgentME/flow,jeffmo/flow,fletcherw/flow,samwgoldman/flow,facebook/flow,samwgoldman/flow,AgentME/flow,gabelevi/flow,ylu1317/flow,mroch/flow,nmote/flow,TiddoLangerak/flow,jgrund/flow,mroch/flow,jamesgpearce/flow,fletcherw/flow,jeffmo/flow,ylu1317/flow,mroch/flow,facebook/flow,jeffmo/flow,chenglou/flow,claudiopro/flow,mroch/flow,ForbesLindesay/flow,AgentME/flow,mroch/flow,gabro/flow,nmote/flow,AgentME/flow,nmote/flow,gabelevi/flow,claudiopro/flow,facebook/flow,nmote/flow,JonathanUsername/flow,jamesgpearce/flow,ForbesLindesay/flow,popham/flow,nmote/flow,jamesgpearce/flow,MichaelDeBoey/flow,AprilArcus/flow,JonathanUsername/flow