replace tab by spaces

docker-compose.yml

@@ -21,8 +21,8 @@ services:
             POSTGRES_USER: "${DB_USER}"
             POSTGRES_PASSWORD: "${DB_PASSWORD}"
         ports:
-			- "${DB_PORT}:5432"
-		volumes:
+            - "${DB_PORT}:5432"
+        volumes:
             - db:/var/lib/postgresql/data:z
         restart: unless-stopped