Ocis docker compose - my own volume for data?

Hi

Ive got a question about the docker compose file to deploy an ocis instance.
I cant find documentation about how to add my own volume?

so Ocis has 2 volume like:
```
- /config:/etc/ocis
- /data:/var/lib/ocis
```

but it looks like it is used for ocis application data/config only.
I need to mount my own volume so I can access my own data in Ocis

How to add an own volume for my own data?

Thanks