help the user about rst_formatting possible dep

src/common/config.py

@@ -92,7 +92,7 @@ class Config:
 		'show_ascii_formatting_chars': [ opt_bool, True , _('If True, do not '
 			'remove */_ . So *abc* will be bold but with * * not removed.')],
 		'rst_formatting_outgoing_messages': [ opt_bool, False,
-			_('Uses ReStructured text markup for HTML, plus ascii formatting if selected.')],
+			_('Uses ReStructured text markup for HTML, plus ascii formatting if selected. (You may need to install docutils)')],
 		'sounds_on': [ opt_bool, True ],
 		# 'aplay', 'play', 'esdplay', 'artsplay' detected first time only
 		'soundplayer': [ opt_str, '' ],