Add keystroke command interface

[JosiahParry]

At the moment I am trying to add cmd + enter command with a leptos app that is using monaco. It is not clear how to do this using the current API. I found an example (below) that uses quite a bit of witch craft that I cannot follow.

https://github.com/abesto/clox-rs/blob/8d6428da1f0a2253e37a003544bec1f86c544b49/web/src/main.rs#L177