fix markup

Doc/library/asyncore.rst

@@ -223,19 +223,20 @@ any that have been added to the map during asynchronous service) is closed.
       garbage-collected.
 
 .. class:: file_dispatcher()
+
   A file_dispatcher takes a file descriptor or file object along with an
   optional map argument and wraps it for use with the :cfunc:`poll`\ or
   :cfunc:`loop`\ functions.  If provided a file object or anything with a
   :cfunc:`fileno`\ method, that method will be called and passed to the
-  :class:`file_wrapper` constructor.
-  Availability: UNIX
+  :class:`file_wrapper` constructor.  Availability: UNIX
+
+.. class:: file_wrapper()
 
-.. class::file_wrapper()
   A file_wrapper takes an integer file descriptor and calls os.dup() to
   duplicate the handle so that the original handle may be closed independently
   of the file_wrapper.  This class implements sufficient methods to emulate a
-  socket for use by the file_dispatcher class.
-  Availability: UNIX
+  socket for use by the file_dispatcher class.  Availability: UNIX
+
 
 .. _asyncore-example: