[Feature Request] Allow mutagen-compose to use relative and absolute path mapping

[blueprismo]

I am forced to use mutagen-compose as I use the crappy Mac chipset everybody is worshipping.

I would like to see if I could use the x-mutagen section with the relative path and not use a named volume like:

  web:
    ...
    volumes:
      - code:/code             # <------------- I would LOVE this to be ./custompath:/code
  
# Define synchronization and forwarding sessions
x-mutagen:
  sync:
    defaults:
      ignore:
        vcs: true
    code:
      alpha: "."
      beta: "volume://code"

Would it be possible to have such approach?