service.8: Use entire section of literally displayed text

.Dl indents literal display text for one line, but .Bd can do it for a
whole subsection.

Pointy hat to:	debdrup
Reported by:	0mp
Reviewed by:	0mp
Differential Revision:	https://reviews.freebsd.org/D28198

usr.sbin/service/service.8

@@ -132,9 +132,11 @@ service -rv
 The following programmable completion entry can be used in
 .Xr csh 1
 for the names and common commands of the rc.d scripts:
-.Dl "complete service 'c/-/(e l r v)/' 'p/1/`service -l`/' \e"
-.Dl "	'n/*/(start stop reload restart \e"
-.Dl "	status rcvar onestart onestop)/'"
+.Bd -literal -offset indent
+complete service 'c/-/(e l r v)/' 'p/1/`service -l`/' \e
+		 'n/*/(start stop reload restart \e
+		 status rcvar onestart onestop)/'
+.Ed
 .Pp
 The following programmable completion entry can be use in
 .Xr bash 1