Move appservice howto into whats-next; again, rename placeholder TURN url

DEPLOY.md

@@ -245,10 +245,13 @@ $ curl https://your.server.name:8448/_matrix/client/versions
 ```
 
 - To check if your server can talk with other homeservers, you can use the [Matrix Federation Tester](https://federationtester.matrix.org/)
-- If you want to set up an appservice, take a look at the [Appservice Guide](APPSERVICES.md).
 
 # What's next?
 
 ## Audio/Video calls
 
 For Audio/Video call functionality see the [TURN Guide](TURN.md).
+
+## Appservices
+
+If you want to set up an appservice, take a look at the [Appservice Guide](APPSERVICES.md).

TURN.md

@@ -8,8 +8,8 @@
 
 ```
 # Refer to your Coturn settings. 
-# `server.name` has to match the REALM setting of your Coturn as well as `transport`.
-turn_uris = ["turn:server.name?transport=udp", "turn:server.name?transport=tcp"]
+# `your.turn.url` has to match the REALM setting of your Coturn as well as `transport`.
+turn_uris = ["turn:your.turn.url?transport=udp", "turn:your.turn.url?transport=tcp"]
 
 # static-auth-secret of your turnserver
 turn_secret = "ADD SECRET HERE"