commit right version this time :-)

Author: JornVernee

mx_commands.py

@@ -126,9 +126,13 @@ def command_function(self):
         return self._command_function
 
     def get_doc(self):
+        doc = self.command_function.__doc__
+        format_args = []
+        if self.usage_msg:
+            format_args.append(self.usage_msg)
         if self.doc_function:
-            return doc_function()
-        return ''
+            format_args.append(self.doc_function())
+        return doc.format(*format_args)
 
     def __call__(self, *args, **kwargs):
         for callback in self._mx_commands.command_before_callbacks: