Update mappings configuration example

roles/matrix-bridge-appservice-irc/defaults/main.yml

@@ -235,7 +235,11 @@ matrix_appservice_irc_ircService_servers: []
 #       # 1:many mappings from IRC channels to room IDs on this IRC server.
 #       # The matrix room must already exist. Your matrix client should expose
 #       # the room ID in a "settings" page for the room.
-#       "#thepub": ["!kieouiJuedJoxtVdaG:localhost"]
+#       "#thepub":
+#         roomIds: ["!kieouiJuedJoxtVdaG:localhost"]
+#         # Channel key/password to use. Optional. If provided, matrix users do
+#         # not need to know the channel key in order to join the channel.
+#         # key: "secret"
 
 #     # Configuration for virtual matrix users. The following variables are
 #     # exposed: