Fixed checkboxes in readme roadmap.
Fixed checkboxes in readme roadmap.

druti/react-quill,tausch86/react-quill-es6,WJWang/react-quill,thr0w/react-quill,favorit/react-quill,bORm/react-quill,hampsterx/react-quill,jure/react-quill,kkerr1/react-quill,thr0w/react-quill,Wattenberger/react-quill,tausch86/react-quill-es6,kkerr1/react-quill,yetone/react-quill,RayOconnor/react-quill,zenoamaro/react-quill,bORm/react-quill,favorit/react-quill,lramsey/react-quill,yetone/react-quill,Wattenberger/react-quill,RayOconnor/react-quill,groenlid/react-quill,zenoamaro/react-quill,WJWang/react-quill,jure/react-quill,groenlid/react-quill,lramsey/react-quill,druti/react-quill,hampsterx/react-quill