Added port via env

docker-compose.yml

@@ -1,3 +1,5 @@
+version: '3.8'
+
 services:
   portfolio:
     build:
@@ -6,7 +8,9 @@ services:
     image: application-portfolio
     container_name: portfolio
     ports:
-      - "5000:5000"
+      - "${PORT:-5000}:5000"
     volumes:
       - ./app:/app
+    environment:
+      - PORT=${PORT:-5000}
     restart: unless-stopped