Add deploy settings for server

docs/.env

@@ -0,0 +1,2 @@
+# Hostname passed to Traefik
+ADDRESS=docs.mailu.io

docs/docker-compose.yml

@@ -4,18 +4,25 @@ version: '3'
 services:
   docs_master:
     image: mailu/docs:master
+    networks:
+      - web
     labels:
       - traefik.enable=true
       - traefik.port=80
-      - traefik.main.frontend.rule=Host:${hostname};PathPrefix:/master/
+      - traefik.main.frontend.rule=Host:${ADDRESS};PathPrefix:/master/
 
   docs_15:
     image: mailu/docs:1.5
+    networks:
+      - web
     labels:
       - traefik.enable=true
       - traefik.port=80
       - traefik.root.frontend.redirect.regex=.*
       - traefik.root.frontend.redirect.replacement=/1.5/
-      - traefik.root.frontend.rule=Host:${hostname};PathPrefix:/
-      - traefik.main.frontend.rule=Host:${hostname};PathPrefix:/1.5/
+      - traefik.root.frontend.rule=Host:${ADDRESS};PathPrefix:/
+      - traefik.main.frontend.rule=Host:${ADDRESS};PathPrefix:/1.5/
 
+networks:
+  web:
+    external: true