bsdconfig.8: add "console dialog" to description

This matches what is commonly done where curses utilites
usually say curses in the description. Line utilities are
very different from screen based utilites. Also, many users
will be searching for graphical utilities, which isn't here.

MFC after:	3 days

usr.sbin/bsdconfig/bsdconfig.8

@@ -1,3 +1,6 @@
+.\"-
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
 .\" Copyright (c) 2012 Ron McDowell
 .\" Copyright (c) 2012-2013 Devin Teske
 .\" All rights reserved.
@@ -28,7 +31,7 @@
 .Os
 .Sh NAME
 .Nm bsdconfig
-.Nd system configuration utility
+.Nd system configuration console dialog utility
 .Sh SYNOPSIS
 .Nm
 .Op Fl h