Description of the new feature/enhancement

Like how I can open a new command prompt with a command arg passed start cmd.exe /k echo Hello, World.

This does not work using Windows Terminal preview start C:\Users\me\AppData\Local\Microsoft\WindowsApps\Microsoft.WindowsTerminal_8wekyb3d8bbwe\wt /k Hello, World

Proposed technical implementation details (optional)

Implement this using cmd.exe like syntax.
start C:\Users\me\AppData\Local\Microsoft\WindowsApps\Microsoft.WindowsTerminal_8wekyb3d8bbwe\wt /k Hello, World.

or even better start wt /k Hello, World.