Fix broken link in modules docs
Fix broken link in modules docs

Summary:
Fixes https://github.com/facebook/flow/issues/1958
Closes https://github.com/facebook/flow/pull/1960

Differential Revision: D3445047

Pulled By: mroch

fbshipit-source-id: 73d1b9505bab5cf980476d824ab978f0d0d69b0f

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