Displays this help menu.

def command_help(self, *args, **kwargs):
        """Displays this help menu."""
        print("Commands available:\n")
        for name in dir(self):
            if not name.startswith("command_"):
                continue
            name_clean = name[len("command_"):]
            print("%s:\n - %s\n" % (name_clean, getattr(self, name).__doc__.strip()))