Logging documentation update.

Doc/library/logging.rst

@@ -564,8 +564,9 @@ Programmers can configure logging in three ways:
 3. Creating a dictionary of configuration information and passing it
    to the :func:`dictConfig` function.
 
-The following example configures a very simple logger, a console
-handler, and a simple formatter using Python code::
+For the reference documentation on the last two options, see :ref:`config-ref`.
+The following example configures a very simple logger, a console handler, and
+a simple formatter using Python code::
 
     import logging
 
@@ -3761,6 +3762,8 @@ with the :mod:`warnings` module.
    (i.e. those in effect before `captureWarnings(True)` was called).
 
 
+.. _config-ref:
+
 Configuration
 -------------