Issue #23730: Document the return value of ZipFile.extract

Patch by Stéphane Wirtel.
diff --git a/Doc/library/zipfile.rst b/Doc/library/zipfile.rst
index 535552d..f3e54ca 100644
--- a/Doc/library/zipfile.rst
+++ b/Doc/library/zipfile.rst
@@ -253,6 +253,8 @@
    to extract to.  *member* can be a filename or a :class:`ZipInfo` object.
    *pwd* is the password used for encrypted files.
 
+   Returns the normalized path created (a directory or new file).
+
    .. note::
 
       If a member filename is an absolute path, a drive/UNC sharepoint and