network firewall IP info update

updated full install doc and corresponding inventory file with the IP info needed for a production install with a network firewall. With the network firewall the app server and monitor servers are on separate network segments.
Was trying to make point that the admin needs to assign an IP address to each of the internal network firewall interfaces. 
Network firewall:
 - Upstream port: dhcp
 - LAN: mon server plugs in (192.168.2.1)
 - OPT1: app server plugs in. (192.168.1.1)

We also want to make sure that the mon server is plugged into the LAN port on the netgate and not the app server. There is a default rule applied to just the LAN interface on the netgates and not the OPT1 interface. That default rule allows the firewall configuration to be accesses by devices off the LAN port.