Clarify the import in docs
Clarify the import in docs

Fixes https://github.com/gaearon/react-dnd/issues/263
longlho/react-dnd,tomulin1/react-dnd,srajko/react-dnd,tylercollier/react-dnd-demo,jgable/react-dnd,longlho/react-dnd,wagonhq/react-dnd,numso/react-dnd,globexdesigns/react-dnd,globexdesigns/react-dnd,jgable/react-dnd,randrianov/react-dnd,srajko/react-dnd,randrianov/react-dnd,tomulin1/react-dnd,tylercollier/react-dnd-demo,numso/react-dnd,wagonhq/react-dnd