Fix markup in README.md.

README.md

@@ -62,7 +62,9 @@ default to *delete* remote emails from the server once they are converted - be
 careful with that. You might want to consider setting up your crontab
 something like this:
 
+```
   @hourly getmail --verbose | logger
+```
 
 This will ensure that getmail is invoked hourly to fetch email, and log its
 output to syslog.