Allow "docker attach" to be shell command

[DanTheMan827]

If I add -i as an extra argument, I can use a command like "docker attach --sig-proxy=false my_container" to get an interactive console of the docker entry point.

 

It would be convenient for things like game servers if you could get the same functionality by just clicking the icon for the container and then "Console"

 

I tried changing the shell command, but you can only select shell or bash, a custom option would also allow the desired functionality since it could be set to the aforementioned docker attach command