Packages.csv: Add new PPS-N package

Add new package "Pharmacy Product System - National" created by patch
"PREN*1*1".  It does not document the namespace prefix or add routines,
so guess "PREN" for now based on the name of the patch.
Add Patches/<package>/README.rst files

Add a README.rst to each package directory to document its purpose and
reference the top-level README.rst file.  This will aid users that
arrive in a repository browser through a link pointing directly at a
package directory.

Use the following shell code to create the files from Packages.csv:

tail -n +2 Packages.csv |
egrep '^[^,]+' |
while IFS=, read pkg dir _; do
  mkdir -p "Packages/$dir" &&
  hdr="VistA: $pkg"
  line="$(echo "$hdr"|sed 's/./=/g')" &&
  readme="Packages/$dir/README.rst" &&
  echo >"$readme" \
"$line
$hdr
$line"'

This directory facilitates development and distribution of a VistA package.

See `<../../README.rst>`__ for more information.

-------
Patches
-------

The `<Patches>`__ directory contains patch host files for the package
organized into subdirectories named for each patch.'
done
Add Patches/<package>/Patches/README.rst files

Add a README.rst to each package Patches directory to document its
purpose and reference the package README.rst file.  This will aid users
that arrive in a repository browser through a link pointing directly at
a package Patches directory.

Use the following shell code to create the files from Packages.csv:

tail -n +2 Packages.csv |
egrep '^[^,]+' |
while IFS=, read pkg dir _; do
  mkdir -p "Packages/$dir/Patches" &&
  echo >"Packages/$dir/Patches/README.rst" \
'This directory contains patch host files for a VistA package.
The files are organized into subdirectories named for each patch.

See `<../README.rst>`__ for package details.'
done