Clarify available array notations
Clarify available array notations

Summary:Mention the availability of `T[]` to annotated arrays in the docs.

Fixes #1537.
Closes https://github.com/facebook/flow/pull/1553

Differential Revision: D3121753

Pulled By: gabelevi

fb-gh-sync-id: 00fb5b3fea41f303194b38680533d257480cf082
fbshipit-source-id: 00fb5b3fea41f303194b38680533d257480cf082

TiddoLangerak/flow,samwgoldman/flow,TiddoLangerak/flow,AgentME/flow,facebook/flow,AprilArcus/flow,fletcherw/flow,jgrund/flow,jdelStrother/flow,gabro/flow,gabelevi/flow,JonathanUsername/flow,jdelStrother/flow,gabro/flow,ForbesLindesay/flow,ForbesLindesay/flow,fletcherw/flow,nmote/flow,samwgoldman/flow,gabro/flow,jamesgpearce/flow,cesarandreu/flow,JonathanUsername/flow,JonathanUsername/flow,claudiopro/flow,jamesgpearce/flow,ylu1317/flow,claudiopro/flow,d14b3l/flow,d14b3l/flow,jamesgpearce/flow,chenglou/flow,AprilArcus/flow,d14b3l/flow,popham/flow,chenglou/flow,facebook/flow,mroch/flow,ForbesLindesay/flow,cesarandreu/flow,samwgoldman/flow,nmote/flow,jeffmo/flow,JonathanUsername/flow,facebook/flow,mroch/flow,claudiopro/flow,jeffmo/flow,fletcherw/flow,claudiopro/flow,jgrund/flow,chenglou/flow,fletcherw/flow,gabro/flow,TiddoLangerak/flow,MichaelDeBoey/flow,MichaelDeBoey/flow,cesarandreu/flow,popham/flow,chenglou/flow,jdelStrother/flow,popham/flow,jeffmo/flow,jeffmo/flow,jamesgpearce/flow,JonathanUsername/flow,MichaelDeBoey/flow,jdelStrother/flow,chenglou/flow,AprilArcus/flow,TiddoLangerak/flow,facebook/flow,ylu1317/flow,AgentME/flow,AprilArcus/flow,MichaelDeBoey/flow,JonathanUsername/flow,fletcherw/flow,gabelevi/flow,jgrund/flow,samwgoldman/flow,mroch/flow,fletcherw/flow,gabro/flow,TiddoLangerak/flow,mroch/flow,AgentME/flow,chenglou/flow,samwgoldman/flow,ForbesLindesay/flow,JonathanUsername/flow,AgentME/flow,ylu1317/flow,popham/flow,AprilArcus/flow,jgrund/flow,nmote/flow,cesarandreu/flow,nmote/flow,nmote/flow,ForbesLindesay/flow,gabelevi/flow,ylu1317/flow,popham/flow,facebook/flow,mroch/flow,AprilArcus/flow,ylu1317/flow,d14b3l/flow,ForbesLindesay/flow,samwgoldman/flow,jamesgpearce/flow,popham/flow,popham/flow,facebook/flow,MichaelDeBoey/flow,mroch/flow,jgrund/flow,jamesgpearce/flow,gabelevi/flow,facebook/flow,jdelStrother/flow,mroch/flow,nmote/flow,d14b3l/flow,gabelevi/flow,gabelevi/flow,claudiopro/flow,jeffmo/flow,jamesgpearce/flow,jdelStrother/flow,gabro/flow,jeffmo/flow,samwgoldman/flow,jgrund/flow,AgentME/flow,nmote/flow,gabelevi/flow,d14b3l/flow