feat: add docker compose to module8

Author: jeastham1993

src/examples/module8/rust_app/docker-compose.yml

@@ -0,0 +1,8 @@
+services:
+  postgres:
+    image: postgres:17-alpine
+    ports:
+      - 5432:5432
+    environment:
+      - POSTGRES_PASSWORD=mysupersecretlocalpassword
+      - POSTGRES_DB=users