docs: def echo_heading(text, marker='=', marker_color='blue'):
      """Print a text formatted to look like a heading.
  
      The output looks like:
      ===> text
      with marker='=' right now.
  
      :param str text: the text to echo
      :param str marker: the marker to mark the heading
      :param str marker_color: one of ('black' | 'red' | 'green' | 'yellow' | 'blue' | 'magenta' | 'cyan' | 'white')
      """
      click.secho(marker * 3 + '>', fg=marker_color, nl=False)
      click.echo(' ' + text)