Added documentation to comms bridge config file.

astrobee/config/communications/comms_bridge.config

@@ -34,6 +34,21 @@ links = {
     -- `from` to `to` direction), relay_backward (to be relayed only in the `to` to `from` direction),
     -- and relay_both (to be relayed in both directions). Providing all three fields gives the user
     -- full directional control while minimizing repetition and copy/paste errors.
+
+    -- Each topic entry can contain an input topic and an output topic. The
+    -- in topic is the topic being published on the robot sending the data and
+    -- must be specified. The optional out topic is the name of the topic a
+    -- user wants the data published on in the receiving robot. If the
+    -- out topic is not specified, the comms bridge will set it to be the name
+    -- of the robot sending the data combined with the in topic name. For
+    -- instance, if the from robot was Bumble and the to robot was Honey and
+    -- one of the in topics in the relay forward list was "mgt/ack", then it
+    -- would be published on Honey on topic "bumble/mgt/ack".
+    -- Please note that only one unique in topic can exist in the relay forward
+    -- and relay both lists and the relay backward and relay both lists. It is
+    -- fine to have the same in topic in the relay forward and relay backward
+    -- lists.
+
     relay_forward = {
       {in_topic = "honey/command", out_topic="command"},
     },