fix(configurator): allow startup without arguments

firmware/tools/configurator/Makefile

@@ -22,8 +22,8 @@ else
 
 help: ## Show configurator commands
 	@printf '%s\n' 'Configurator' '' \
-		'The root Makefile passes every argument after -- to the application:' \
-		'  make firmware/tools/configurator -- --source-system 255 --serial /dev/ttyUSB0 --baud 115200'
+		'Start the local web application, then select the serial device in the browser:' \
+		'  make firmware/tools/configurator'
 
 endif