enable devcontainer up in detached mode

[Jogi7819]

devcontainer up runs per default the command docker run with -a STDOUT and -a STDERR. The command is executed without issues but the bash gets never released and stucks. It would by nice to allow instead of the mentioned paramters to run devcontainer up in detach mode which should result in docker run --detach ...

[Chuxel]

I created devcontainers/cli#430 in the CLI repo to capture the feature request!