added 'binding' attribute to the JSON format doc for counters and meters
added 'binding' attribute to the JSON format doc for counters and meters

hanw/behavioral-model,p4lang/behavioral-model,hanw/behavioral-model,hanw/behavioral-model,p4lang/behavioral-model,p4lang/behavioral-model,hanw/behavioral-model,p4lang/behavioral-model,p4lang/behavioral-model,hanw/behavioral-model