update doc/syntax.txt.
update doc/syntax.txt.

mario-campos/clay,jckarter/clay,iamrekcah/clay,aep/clay,aep/clay,jckarter/clay,mario-campos/clay,aep/clay,mario-campos/clay,jckarter/clay,mario-campos/clay,iamrekcah/clay,jckarter/clay,iamrekcah/clay,iamrekcah/clay,jckarter/clay,aep/clay,jckarter/clay,iamrekcah/clay,aep/clay,mario-campos/clay,aep/clay