Fix penis command docstring

Author: linuxdaemon

plugins/penis.py

@@ -11,7 +11,7 @@
 
 @hook.command("penis", "bepis", autohelp=False)
 def penis(text, message):
-    """much dongs, very ween, add a user nick as an arguement for slightly different 'output'"""
+    """[nick] - much dongs, very ween, add a user nick as an arguement for slightly different 'output'"""
     if not text:
         message("{}{}{}".format(random.choice(balls), random.choice(shaft), random.choice(head)))
     else: