add optional configuration for nginx frontend container

src/docker-compose.yml

@@ -81,6 +81,17 @@ services:
     depends_on:
       - app
 
+  web-nginx:
+    image: cthulhoo/ttrss-web-nginx:latest
+    build: ./web-nginx
+    restart: unless-stopped
+    ports:
+      - ${HTTP_PORT}:80
+    volumes:
+      - app:/var/www/html:ro
+    depends_on:
+      - app
+
 volumes:
   db:
   app: