Add versionchanged and versionadded declarations for changes to metadata.

Author: jaraco

Doc/library/importlib.metadata.rst

@@ -176,6 +176,13 @@ all the metadata in a JSON-compatible form per PEP 566::
     >>> wheel_metadata.json['requires_python']
     '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*'
 
+.. versionchanged:: 3.10
+   The ``Description`` is now included in the metadata when presented
+   through the payload. Line continuation characters have been removed.
+
+.. versionadded:: 3.10
+   The ``json`` attribute was added.
+
 
 .. _version: