docs: def create_jinja_env():
      """Create a Jinja2 `~jinja2.Environment`.
  
      Returns
      -------
      env : `jinja2.Environment`
          Jinja2 template rendering environment, configured to use templates in
          ``templates/``.
      """
      template_dir = os.path.join(os.path.dirname(__file__), 'templates')
      env = jinja2.Environment(
          loader=jinja2.FileSystemLoader(template_dir),
          autoescape=jinja2.select_autoescape(['html'])
      )
      env.filters['simple_date'] = filter_simple_date
      env.filters['paragraphify'] = filter_paragraphify
      return env