docs: def setup(app):
      """
      Setup for Sphinx extension.
  
      :param app: Sphinx application context.
      """
      try:
          app.info('adding bolditalic role...', nonl=True)
          app.add_role('bolditalic', bolditalic)
          app.connect('env-updated', css)
          app.info(' done')
      except Exception:
          app.warn('Failed to initialize bolditalic styling.')
      return {
          'version': __version__,
          'parallel_read_safe': True,
          'parallel_write_safe': True,
          }