Plugin rpi_temp: convert documentation to perlpod format

plugins/raspberry-pi/rpi_temp

@@ -1,5 +1,24 @@
 #! /bin/sh
-# (c) 2013 - LGPL - Steve Schnepp <steve.schnepp@pwkf.org>
+
+: <<=cut
+
+=head1 NAME
+
+rpi_temp - monitor the temperature of a Raspberry device
+
+
+=head1 AUTHORS
+
+Copyright (C) 2013 Steve Schnepp <steve.schnepp@pwkf.org>
+
+
+=head1 LICENSE
+
+GNU Library General Public License v2 only
+
+SPDX-License-Identifier: LGPL-2.0-only
+
+=cut
 
 
 if [ ! -r "/sys/class/thermal/thermal_zone0/temp" ]