Revert "feat: add support for horizontal scaling with multiple back-end...

Revert "feat: add support for horizontal scaling with multiple back-end instances in docker-compose"

This reverts commit f4513562.

docker-compose.yml

-version: '3.9'
 services:
   mongodb:
     image: mongo:latest
@@ -10,28 +9,14 @@ services:
       - MONGO_INITDB_ROOT_PASSWORD=${MONGO_INITDB_ROOT_PASSWORD}
       - MONGO_INITDB_DATABASE=todo-app
 
-  todo-app-1:
+  todo-app:
     build:
       context: .
       dockerfile: Dockerfile
-    container_name: todo-app-1
+    container_name: todo-app
     ports:
-      - "3001:3000"
+      - "80:3000"
     depends_on:
       - mongodb
     environment:
       - MONGO_URI=${MONGO_URI}
-      - PORT=3000
-
-  todo-app-2:
-    build:
-      context: .
-      dockerfile: Dockerfile
-    container_name: todo-app-2
-    ports:
-      - "3002:3000"
-    depends_on:
-      - mongodb
-    environment:
-      - MONGO_URI=${MONGO_URI}
-      - PORT=3000