Add a very basic MUNIN plugin based on the Munin example shell plugin.

For this munin-plugin to work, you must already have "installed" a copy
of TEMPered to /usr/local/bin/tempered.

As TEMPered requires root permissions to access some devices, a
TEMPered.conf.d plugin configuration file is included.  Copy this to the
/etc/munin/plugin-conf.d/ directory on your system.

Either copy the TEMPered munin-plugin file to your /etc/munin/plugins/
directory or take the more common approach of creating a symlink in
there to the munin-plugin/TEMPered file.

Restart your munin-node service and you should see readings begin for
the sensor.

Previously only the first temperature reading was recorded in the Munin
plugin.  This update records each reading in turn.

Many of the other temperature reading plugins for Munin are under the
sesnors category.  If we do not specify a category we get placed under
"other".

Existing temperature reading charts label their vertical axis as Degrees
Celsius.  I would use a degree symbol ° and a capital C but Munin's
support for rendering this seems a little off.

graph_info gives a little background to what the readings on a chart
are.  Add short note explaining where these reading come from.