Runtime cli docs for multicast commands (#794)
Runtime cli docs for multicast commands (#794)

* Add runtime_CLI docs on table_add and a few other commands

* Add documentation on simple_switch_CLI commands for multicast groups

* Fix typo in markup

* Correct a couple of small mistakes

* add missing comma

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