Update docs to reflect that target type restrictions are optional.
Update docs to reflect that target type restrictions are optional.

ericzundel/commons,cevaris/commons,cevaris/commons,WCCCEDU/twitter-commons,atollena/commons,nkhuyu/commons,jsirois/commons,VaybhavSharma/commons,ericzundel/commons,abel-von/commons,WCCCEDU/twitter-commons,Yasumoto/commons,brutkin/commons,pombredanne/commons,nkhuyu/commons,nkhuyu/commons,VaybhavSharma/commons,WCCCEDU/twitter-commons,jsirois/commons,abel-von/commons,pombredanne/commons,cevaris/commons,nkhuyu/commons,jsirois/commons,brutkin/commons,nkhuyu/commons,atollena/commons,brutkin/commons,jsirois/commons,Yasumoto/commons,brutkin/commons,VaybhavSharma/commons,abel-von/commons,cevaris/commons,atollena/commons,VaybhavSharma/commons,abel-von/commons,brutkin/commons,atollena/commons,ericzundel/commons,jsirois/commons,VaybhavSharma/commons,pombredanne/commons,ericzundel/commons,atollena/commons,pombredanne/commons,WCCCEDU/twitter-commons,Yasumoto/commons,Yasumoto/commons,Yasumoto/commons,abel-von/commons,cevaris/commons,pombredanne/commons,WCCCEDU/twitter-commons,ericzundel/commons