fix ReST formatting

Author: ethanfurman

Doc/library/enum.rst

@@ -786,8 +786,8 @@ Utilities and Decorators
       * ``FIRST = auto()`` will work (auto() is replaced with ``1``);
       * ``SECOND = auto(), -2`` will work (auto is replaced with ``2``, so ``2, -2`` is
          used to create the ``SECOND`` enum member;
-      * ``THREE`` = [auto(), -3]`` will *not* work (``auto, -3`` is used to create the
-        ``THREE`` enum member)
+      * ``THREE = [auto(), -3]`` will *not* work (``<auto instance>, -3`` is used to
+        create the ``THREE`` enum member)
 
    ``_generate_next_value_`` can be overridden to customize the values used by
    *auto*.