docs: def update_fmt_with_notebook_options(self, metadata):
          """Update format options with the values in the notebook metadata, and record those
          options in the notebook metadata"""
          # format options in notebook have precedence over that in fmt
          for opt in _VALID_FORMAT_OPTIONS:
              if opt in metadata.get('jupytext', {}):
                  self.fmt.setdefault(opt, metadata['jupytext'][opt])
              if opt in self.fmt:
                  metadata.setdefault('jupytext', {}).setdefault(opt, self.fmt[opt])
  
          # rST to md conversion should happen only once
          if metadata.get('jupytext', {}).get('rst2md') is True:
              metadata['jupytext']['rst2md'] = False