Update docker network web to use wider subnet and restricted DHCP pool

fighter/config/traefik/README.md

@@ -0,0 +1,5 @@
+### The `web` Network
+
+Created with `docker network create --driver=bridge --subnet=172.20.0.0/23 --ip-range=172.20.1.0/24 web`
+
+Previous version was naive, and had a subnet equal in size to the IP range. This meant that we would occasionally encounter address colisions between services which needed static IPs, and those handed IPs automatically. 

fighter/config/traefik/docker-compose.yml

@@ -7,7 +7,7 @@ services:
     restart: "no"
     networks:
       web:
-        ipv4_address: 172.18.0.27
+        ipv4_address: 172.20.0.10
       monitoring: 
     ports:
       - 80:80