docs: simplify to document return type only per review

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Bortlesboat

Doc/library/argparse.rst

@@ -698,9 +698,7 @@ The add_argument() method
 
    * deprecated_ - Whether or not use of the argument is deprecated.
 
-   The method returns the :class:`Action` object that was created and added to
-   the parser.  This can be stored and used for further customization or
-   inspection.
+   The method returns an :class:`Action` object representing the argument.
 
 The following sections describe how each of these are used.