Instructions for mounting Linux guest directories so they are read-writable by the host

### Description

Please provide instructions (or config options) for mounting Linux guest directories so they are read-writable by the host.

For example, I'd like to read-only mount my Linux guest root directory `/` at `/Users/user/.lima/default/root` or read-write mount my Linux guest home directory `/home/user` at `/Users/user/.lima/home`.

I'm guessing this is standard container-foo, but for those of us new to containers it would be helpful to have it in the README or default config.

Thanks!