fix: add volumes to example yml

docker-compose.yml.example

@@ -11,6 +11,9 @@ services:
     image: forge.lys.ee/lyssieth/rave:amd64
     environment:
       DATABASE_URL: postgresql://postgres:postgres@db/rave
+    volumes:
+      - ./storage:/storage:ro
+      - ./cache:/cache:rw
     ports:
       - 8000:1234
     depends_on: