add omitted markup

Doc/tut/tut.tex

@@ -4935,8 +4935,9 @@ This produces the following output:
 By default, informational and debugging messages are suppressed and the
 output is sent to standard error.  Other output options include routing
 messages through email, datagrams, sockets, or to an HTTP Server.  New
-filters can select different routing based on message priority:  DEBUG,
-INFO, WARNING, ERROR, and CRITICAL.
+filters can select different routing based on message priority:
+\constant{DEBUG}, \constant{INFO}, \constant{WARNING}, \constant{ERROR},
+and \constant{CRITICAL}.
 
 The logging system can be configured directly from Python or can be
 loaded from a user editable configuration file for customized logging