add optional configuration for nginx frontend container

docker-compose.yml

@@ -73,6 +73,16 @@ services:
 #    depends_on:
 #      - app
 
+#  web-nginx:
+#    image: cthulhoo/ttrss-web-nginx
+#    restart: unless-stopped
+#    ports:
+#      - ${HTTP_PORT}:80
+#    volumes:
+#      - app:/var/www/html:ro
+#    depends_on:
+#      - app
+
 volumes:
   db:
   app:  

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: