Remove reference to removed Py_digit type

Fix also a typo in long.rst.

Author: vstinner

Doc/c-api/long.rst

@@ -693,7 +693,7 @@ Export API
    This function always succeeds if *obj* is a Python :class:`int` object or a
    subclass.
 
-   If *export_long.digits* is not ``NULL, :c:func:`PyLong_FreeExport` must be
+   If *export_long.digits* is not ``NULL``, :c:func:`PyLong_FreeExport` must be
    called when the export is no longer needed.
 
 

Doc/using/configure.rst

@@ -129,8 +129,7 @@ General Options
 
    Define the ``PYLONG_BITS_IN_DIGIT`` to ``15`` or ``30``.
 
-   See :data:`sys.int_info.bits_per_digit <sys.int_info>` and the
-   :c:type:`Py_digit` type.
+   See :data:`sys.int_info.bits_per_digit <sys.int_info>`.
 
 .. option:: --with-suffix=SUFFIX