Would be useful as a shortcut for opening files.

https://www.electronjs.org/docs/api/app#event-open-file-macos suggests this may be possible through listening to the open-file event:

Emitted when the user wants to open a file with the application. The open-file event is usually emitted when the application is already open and the OS wants to reuse the application to open the file. open-file is also emitted when a file is dropped onto the dock and the application is not yet running. Make sure to listen for the open-file event very early in your application startup to handle this case (even before the ready event is emitted).