Missing documentation/unit tests about protocol options

[renarsvilnis]

Found out by looking at source code there are missing documentation about the protocols option which gets used in electron-packager/mac.js for building electron apps that register custom url scheme on os. Example when opening myapp://blip-blop in browser it passes myapp://blip-blop string as an argument to open-url app module event.

[buddingmonkey]

👍

[max-mapper]

Heres the usage:

--protocol-name=\"MyApp URL\" --protocol=\"myapp\"

This will cause your app.on('open-url') fn to fire when myapp:// links are opened from e.g. Chrome