prosody.cfg.lua.dist: TURN configuration improvements and example

prosody.cfg.lua.dist

@@ -66,7 +66,7 @@ modules_enabled = {
 		"invites_register"; -- Create accounts using invites
 		"invites_adhoc"; -- Create invites via AdHoc command
 		--"mam"; -- Store messages in an archive and allow users to access it
-		--"turn_external"; -- Provide external TURN (and STUN) service
+		--"turn_external"; -- Provide external STUN/TURN service for e.g. audio/video calls
 
 	-- Admin interfaces
 		"admin_adhoc"; -- Allows administration via an XMPP client that supports ad-hoc commands
@@ -161,6 +161,17 @@ archive_expires_after = "1w" -- Remove archived messages after 1 week
 -- You can also configure messages to be stored in-memory only. For more
 -- archiving options, see https://prosody.im/doc/modules/mod_mam
 
+
+-- Audio/video call relay (STUN/TURN)
+-- To ensure clients connected to the server can establish connections for
+-- low-latency media streaming (such as audio and video calls), it is
+-- recommended to run a STUN/TURN server for clients to use. If you do this,
+-- specify the details here so clients can discover it.
+-- Find more information at https://prosody.im/doc/turn
+
+--turn_external_host = "turn.example.com"
+--turn_external_secret = "your-secret-turn-access-token"
+
 -- Logging configuration
 -- For advanced logging see https://prosody.im/doc/logging
 log = {