I'm working on an extension for Visual Studio Code where I also want to add coloring for a language. However, I'd need more scopes than what is usually defined in a theme file. Of course I could also create an own theme to add what I need (via a themes contribution point), but that's not very user friendly. It would be better if I could just append new scopes to colorize to the existing theme via my extension.
Is this possible and how?