Feature request: local install

[jneen]

Hi there!

I'm attempting to integrate our game with the desktop app, and one thing that would be super helpful is the ability to install or run a game from within the context of the desktop app, without having to upload it to itch.io. Something like butler local-install <manifest>. Pie-in-the-sky would be a symlinked install, for fast local testing within the app.

Cheers!
Jeanine