docs: def create_keytype_item_node(field, state):
      """Create a definition list item node that describes the key type
      of a dict-type config field.
  
      Parameters
      ----------
      field : ``lsst.pex.config.Field``
          A ``lsst.pex.config.DictField`` or ``lsst.pex.config.DictConfigField``.
      state : ``docutils.statemachine.State``
          Usually the directive's ``state`` attribute.
  
      Returns
      -------
      ``docutils.nodes.definition_list_item``
          Definition list item that describes the key type for the field.
      """
      keytype_node = nodes.definition_list_item()
      keytype_node = nodes.term(text='Key type')
      keytype_def = nodes.definition()
      keytype_def += make_python_xref_nodes_for_type(
          field.keytype,
          state,
          hide_namespace=False)
      keytype_node += keytype_def
      return keytype_node