Update sample code block to simplify docs.
Update sample code block to simplify docs.

firebase/quickstart-js,yochannah/trafficuk,robforee/YA,jmarantz/soccersub,uhntiss/quickstart-js,uhntiss/quickstart-js,jmarantz/soccersub,robforee/YA,jmarantz/soccersub,knohyou/ExRx.net,robforee/YA,uhntiss/quickstart-js,theGove/atlas,knohyou/ExRx.net,DES157/quickstart-js,firebase/quickstart-js,theGove/atlas,DaryaBeda/firebase_,DES157/quickstart-js,DaryaBeda/firebase_,yochannah/trafficuk,firebase/quickstart-js