Updating install instructions

src/freedombone-prep

 echo ''
 echo 'Finally you can use the freedombone command to install a server configuration:'
 echo ''
-echo "    freedombone --bbb -d [domain] -u [username] --ip $BBB_FIXED_IP_ADDRESS --iprouter $ROUTER_IP_ADDRESS"
+echo "    freedombone --bbb -d [domain] -u [username] --ip $BBB_FIXED_IP_ADDRESS --iprouter $ROUTER_IP_ADDRESS --ddns [dynamic DNS provider domain] --ddnsuser [dynamic DNS username] --ddnspass [dynamic DNS password]"
 echo ''
 echo 'See the manpage for more information on how to use the freedombone command.'
 exit 0