prosody: add support for lobby

env.example

@@ -49,6 +49,8 @@ TZ=UTC
 # See the "Running behind NAT or on a LAN environment" section in the README
 #DOCKER_HOST_ADDRESS=192.168.1.1
 
+# Control whether the lobby feature should be enabled or not
+#ENABLE_LOBBY=1
 
 #
 # Let's Encrypt configuration
@@ -94,7 +96,7 @@ TZ=UTC
 #JIGASI_SIP_TRANSPORT=UDP
 
 #
-# Authentication configuration (see README for details)
+# Authentication configuration (see handbook for details)
 #
 
 # Enable authentication