Feature request: Allow dynamic "runArgs" for docker

Could you somehow support a way of building and passing dynamic arguments to the docker run command? We currently only have runArgs array in devcontainer.json that is static in nature and not suitable for any sort of scripting. One use case could be, for example, to mount some extra volumes conditionally while keeping all the nice automatic devcontainer infrastructure that the remote extension has to offer. It'd be enough just to include a shell call somewhere. For example, you could introduce a string version of runArgs that would be included verbatim in the default docker run command and then the entire command would be executed by the shell. Or you could introduce a runCommand override with some pre-defined variables that users would then include in the command they specify. You could also support variables like ${workspaceFolder} in remote.containers.dockerPath so that we can hack our way through :) Thanks