added grunt-cli to the README
added grunt-cli to the README

apache/cordova-registry-web,rakatyal/Cordova-Registry-Web-Fork,apache/cordova-registry-web,apache/cordova-registry-web,revolunet/cordova-registry-web,rakatyal/Cordova-Registry-Web-Fork,revolunet/cordova-registry-web,rakatyal/Cordova-Registry-Web-Fork,revolunet/cordova-registry-web