Issue #11794: Reorganised logging documentation.

Doc/howto/index.rst

@@ -19,6 +19,8 @@ Currently, the HOWTOs are:
    descriptor.rst
    doanddont.rst
    functional.rst
+   logging.rst
+   logging-cookbook.rst
    regex.rst
    sockets.rst
    sorting.rst

Doc/library/allos.rst

@@ -20,6 +20,8 @@ but they are available on most other systems as well.  Here's an overview:
    optparse.rst
    getopt.rst
    logging.rst
+   logging.config.rst
+   logging.handlers.rst
    getpass.rst
    curses.rst
    curses.ascii.rst