docs: def create_field_type_item_node(field, state):
      """Create a definition list item node that describes a field's type.
  
      Parameters
      ----------
      field : ``lsst.pex.config.Field``
          A configuration field.
      state : ``docutils.statemachine.State``
          Usually the directive's ``state`` attribute.
  
      Returns
      -------
      ``docutils.nodes.definition_list_item``
          Definition list item that describes a field's type.
      """
      type_item = nodes.definition_list_item()
      type_item.append(nodes.term(text="Field type"))
      type_item_content = nodes.definition()
      type_item_content_p = nodes.paragraph()
      type_item_content_p += make_python_xref_nodes_for_type(
          type(field),
          state,
          hide_namespace=True)[0].children
      if field.optional:
          type_item_content_p += nodes.Text(' (optional)', ' (optional)')
      type_item_content += type_item_content_p
      type_item += type_item_content
      return type_item