I've got a shared monorepo setup where I have a backend, frontend, and shared packages. Right now I'm not using dockerfiles or railway.toml, I'm just using the default behaviour and using custom build and run commands for the frontend and backend. However, I need to install libssl on the backend, so I need to use a dockerfile. What's the right configuration for me to continue using a shared monorepo setup but also use a dockerfile for my backend? (and maybe a dockerfile for the frontend in the future if needed)