Support for custom user/group id

[ghost]

I'd really like to see an update where setting custom user/group id in the docker-compose file for the volume files is supported. The nginx default of 101:101 maps to sensitive ids on my host.

Either through the user: UID:GID directive of docker compose or through environment variables (linuxserver.io images do this well).

[gilbsgilbs]

The nginx default of 101:101 maps to sensitive ids on my host.

Isn't this a good use-case for userns-remap?