feat: adds the required config for using GitHub as an updater provider

[danjohnson95]

Adds config to the nativephp.php config file for configuring GitHub as an updater provider.

This is required with my PR here - NativePHP/electron#75

[mpociot]

That's great, thank you!
Could you also add all the environment files to the config, which should automatically be removed when bundling the app?

https://github.com/NativePHP/laravel/blob/main/config/nativephp.php#L46-L54

I'm pretty sure all of these can be removed, as they are not needed in the actual PHP application when it's bundled to be used within NativePHP. Otherwise users will accidentally leak their GitHub token

[mpociot]

Thanks 👍