code: def show_command_line_usage(parser, usage=False):
      
      help_header_message = get_command_header(parser, "command", usage)
      loader = template.Loader(os.path.join(
          firenado.conf.ROOT, 'management', 'templates', 'help'))
      command_template = "  {0.name:15}{0.description:40}"
      help_message = loader.load("main_command_help.txt").generate(
          command_categories=command_categories,
          command_template=command_template
      ).decode(sys.stdout.encoding)
      # TODO: This print has to go. Use proper stream instead(stdout or stderr)
      print(''.join([help_header_message, help_message]))
docs: Show the command line help