[wip] passing node-notifier options

[Gvozd]

• testing direct passing otpions
• document it
• support custom sub-options like

new WebpackNotifierPlugin ({
  notifier: 'NotificationCenter',// or constructor - require('node-notifier').NotificationCenter
  notifierOptions: {
    withFallback: false,
    customPath: undefined
  },
  notifyOptions: {
    appID: 'com.squirrel.your.app'
  }
});

[Nothing-Works]

@Gvozd maybe just one little thing, I think you should consider user appID as the key rather than appId as appID is matching the exact key from node-notifier. see here

[Gvozd]

@Nothing-Works Yes, I sealed
of course the appID is correct

corrected the test