Plugin dartybox: convert documentation to perlpod format

plugins/router/dartybox

@@ -1,11 +1,32 @@
 #! /bin/sh
-# Parse box information
-# (c) 2013 - GPLv2 - Steve Schnepp <steve.schnepp@pwkf.org>
-#
-# Configuration is done via ENV vars, here is the default :
-#
-# [dartybox]
-# env.IP 192.168.1.254
+
+: <<=cut
+
+=head1 NAME
+
+dartybox - parse router information
+
+
+=head1 CONFIGURATION
+
+The following default configuration is used:
+
+ [dartybox]
+ env.IP 192.168.1.254
+
+
+=head1 AUTHORS
+
+Copyright (C) 2013 Steve Schnepp <steve.schnepp@pwkf.org>
+
+
+=head1 LICENSE
+
+GNU Library General Public License v2 only
+
+SPDX-License-Identifier: GPL-2.0-only
+
+=cut
 
 
 . $MUNIN_LIBDIR/plugins/plugin.sh