Doc: Change the "..." glossary entry to mention the Ellipsis object

Author: adorilson

Doc/glossary.rst

@@ -21,7 +21,9 @@ Glossary
         right delimiters (parentheses, square brackets, curly braces or triple
         quotes), or after specifying a decorator.
 
-      * The :const:`Ellipsis` built-in constant.
+      .. index:: single: ...; ellipsis literal
+
+      * The three dots form of the :ref:`Ellipsis <bltin-ellipsis-object>` object.
 
    abstract base class
       Abstract base classes complement :term:`duck-typing` by