docs: def render(template_path, output_file=None, **kwargs):
      """
      Render jinja2 template file use absolute path.
  
      **Usage**
  
      A simple template as follow:
  
      .. code-block:: jinja
  
          This is a test template
  
          {{ title }}
  
      Then write render code by single line.
  
      .. code-block:: python
  
          render('template.tpl', name='toolkit')
  
      :param template_path: absolute file path of template file.
      :param output_file: the path of output file.
      :param kwargs: keyword arguments for template.
      """
      template = get_template(template_path)
      rendered = template.render(**kwargs)
      if not output_file:
          return rendered
      with open(output_file) as f:
          f.write(rendered)