Fix label in docs (from issue #13538).

Doc/reference/datamodel.rst

@@ -1153,7 +1153,7 @@ Basic customization
    Called by :func:`str(object) <str>` and the built-in functions
    :func:`format` and :func:`print` to compute the "informal" or nicely
    printable string representation of an object.  The return value must be a
-   :ref:`string <textseq>` object.
+   :ref:`string <typesseq>` object.
 
    This method differs from :meth:`object.__repr__` in that there is no
    expectation that :meth:`__str__` return a valid Python expression: a more