To install Greenstone3 as a service, run:

sudo ./INSTALL-SERVICE.sh [user] [service-name]

The two parameters are optional. The defaults are
 - user : www-data
 - service name : greenstone3

Change the service name eg if you want to have more than one greenstone service running
(eg greenstone3-foo, greenstone3-bar)

This script checks a few things first, and if all is well, goes ahead and
creates the <service-name>.service file (in this folder), and then installs
it into /etc/systemd/system

It finishes by printing out some extra details, such as how to use the
service with 'systemctl', including how to add it in to the boot-up
sequence.