docs: def readme_template(readme_template_file):
      """Display / set / update the readme template file."""
      if not readme_template_file:
          click.secho(dtool_config.utils.get_readme_template_fpath(
              CONFIG_PATH,
          ))
      else:
          click.secho(dtool_config.utils.set_readme_template_fpath(
              CONFIG_PATH,
              readme_template_file
          ))