Push Notifications docs manly refers only to Ionic apps and not to plain Cordova apps:

• where should I put the `google-services.json`
• where should I put the `mobile-services.json`
• from where is `PushNotification.init(..` coming (https://github.com/phonegap/phonegap-plugin-push)
• how to handle `PushNotification.init` errors (`push.on('error', (e) => {})`)
• where do I set alias and categories (maybe a link to @aerogear/push API doc)
• how do I subscribe to notification if I use plain Cordova (`push.on("notification", (notification) => {})`)