[FAB-4296] Document core.yaml gossip bootstrapPeers

Bootstrap peers need to be in the same org as the peer,
or else there is a danger that the peer would send its
internal endpoint to the bootstrap peer when it's in a different org.

Change-Id: I5d7f3a5fb0ceec18035a470e92f45438d7a57307
Signed-off-by: Yacov Manevich <[email protected]>

Author: yacovm

sampleconfig/core.yaml

@@ -71,7 +71,11 @@ peer:
 
     # Gossip related configuration
     gossip:
-        # Bootstrap set to initialize gossip with
+        # Bootstrap set to initialize gossip with.
+        # This is a list of peers that the peer reaches out to at startup.
+        # Important: The endpoints here have to be endpoints of peers in the same
+        # organization, because the connection establishment process to these peers
+        # exposes the internal endpoint of this peer.
         bootstrap: 127.0.0.1:7051
 
         # NOTE: orgLeader and useLeaderElection parameters are mutual exclusive