Update internal room ID: !someRoom

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

roles/custom/matrix-alertmanager-receiver/defaults/main.yml

@@ -127,8 +127,8 @@ matrix_alertmanager_receiver_config_matrix_access_token: ''
 #
 # Example:
 # matrix_alertmanager_receiver_config_matrix_room:
-#   simple-name: "!qohfwef7qwerf:example.com"
-#   another-name: "!bf3zfio3wbanw:example.com"
+#   simple-name: "!someRoom:example.com"
+#   another-name: "!anotherRoom:example.com"
 matrix_alertmanager_receiver_config_matrix_room_mapping: {}
 
 # Controls the `templating.external-url-mapping` configuration setting.