feat: Add docker-compose

docker-compose.yml

@@ -0,0 +1,12 @@
+version: '3'
+
+services:
+    postgres-db:
+        image: postgres:15
+        container_name: postgres-db
+        environment:
+            - POSTGRES_PASSWORD=postgres
+            - POSTGRES_USER=postgres
+            - POSTGRES_DB=grades
+        ports:
+            - "5432:5432"