[3.10] bpo-43184: Add information about added attribute and method. (GH-27347) (GH-27355)

(cherry picked from commit 50b7276)

Author: miss-islington

Doc/library/logging.rst

@@ -900,6 +900,10 @@ interchangeably.
    :meth:`~Logger.setLevel` and :meth:`~Logger.hasHandlers` methods were added
    to :class:`LoggerAdapter`.  These methods delegate to the underlying logger.
 
+.. versionchanged:: 3.6
+   Attribute :attr:`manager` and method :meth:`_log` were added, which
+   delegate to the underlying logger and allow adapters to be nested.
+
 
 Thread Safety
 -------------