docs(firebase-analytics): update (#194)

* docs(firebase-analytics): update

* chore: update

* chore: update

* chore: update

* chore: update

* docs(firebase-analytics): update

Author: Ombuweb

packages/firebase-analytics/README.md

@@ -1,5 +1,21 @@
 # @nativescript/firebase-analytics
 
+* [Intro](#intro)
+* [Installation](#installation)
+* [Use @nativescript/firebase-analytics](#use-nativescriptfirebase-analytics)
+	* [Log custom events](#log-custom-events)
+	* [Log Predefined Events](#log-predefined-events)
+	* [Reserved Events](#reserved-events)
+	* [Get the app instance id](#get-the-appinstance-id)
+	* [Disable Ad Id usage on iOS](#disable-ad-id-usage-on-ios)
+	* [Demo app](#demo-app)
+* [Analytics class](#analytics-class)
+	* [Properties](#properties)
+	* [Methods](#Methods)
+* [License](#License)
+
+## Intro
+
 This plugin allows you to add [Google Analytics for Firebase](https://firebase.google.com/docs/analytics)
  to your app. 
 
@@ -13,18 +29,6 @@ Analytics collects usage and behavior data for your app. Its two primary concern
 
 [![image](https://img.youtube.com/vi/8iZpH7O6zXo/hqdefault.jpg)](https://www.youtube.com/watch?v=8iZpH7O6zXo)
 
-* [Installation](#installation)
-* [Use @nativescript/firebase-analytics](#use-nativescriptfirebase-analytics)
-	* [Log custom events](#log-custom-events)
-	* [Log Predefined Events](#log-predefined-events)
-	* [Reserved Events](#reserved-events)
-	* [Get the app instance id](#get-the-appinstance-id)
-	* [Disable Ad Id usage on iOS](#disable-ad-id-usage-on-ios)
-* [Analytics class API](#analytics-class-api)
-	* [Properties](#properties)
-	* [Methods](#Methods)
-* [License](#License)
-
 ## Installation
 Install the plugin by running the following command in the root directory of your project.
 
@@ -39,7 +43,8 @@ The examples below show you how to use `@nativescript/firebase-analytics` to log
 ### Log custom events
 
 Analytics also allows developers to log custom events. If you're already familiar with Google Analytics, this method is equivalent to using the event command in [gtag.js](https://developers.google.com/gtagjs/).
-To log a custom event to Analytics, call the `logEvent` method on an instance of the `Analytics` class passing it the name of the custom event as the first argument and the event data object as the second argument.
+
+To log a custom event to Analytics, call the `logEvent` method on an instance of the [Analytics](#analytics-class) class passing it the name of the custom event as the first argument and the event data object as the second argument.
 
 Please be aware that primitive data types or arrays of primitive data types are logged in your Firebase Analytics console.
 
@@ -105,9 +110,9 @@ import { firebase } from '@nativescript/firebase-core';
 const appInstanceId = firebase().analytics().getAppInstanceId();
 ```
 
-### Disable Ad Id usage on iOS
+### Disable Identifier for Advertisers usage with analytics on iOS
 
-Apple strictly bans an app from being in the Kids category if the app accesses IDFA iOS symbols.
+Apple strictly bans an app from being in the Kids category if the app accesses Identifier for Advertisers(IDFA) iOS symbols.
 
 Additionally, if an app accesses IDFA iOS symbols, it must implement Apple's [App Tracking Transparency](https://developer.apple.com/documentation/apptrackingtransparency)(or `ATT`). However, if an app does not use IDFA and otherwise handles data in an ATT-compatible way, it eliminates this ATT requirement.
 
@@ -119,9 +124,13 @@ $NSFirebaseAnalyticsWithoutAdIdSupport = true
 
 During pod install, using that variable installs a new `Analytics With No Ad Ids` pod that the firebase-ios-sdk team created, and allows both the use of Firebase Analytics in Kids Category apps and Firebase Analytics without needing the App Tracking Transparency handling (assuming no other parts of your app handles data in a way that requires ATT)
 
-Note that for obvious reasons, configuring Firebase Analytics for use without IDFA is incompatible with AdMob.
+>**Note** that configuring Firebase Analytics for use without IDFA is incompatible with AdMob.
+
+### Demo app
+
+You can find the demo app [here](https://stackblitz.com/edit/nativescript-stackblitz-templates-j2k32w?file=app/firebase-analytics-page.ts).
 
-## Analytics class API
+## Analytics class 
 
 The plugin offers you the Analytics class through which you can manage Firebase Analytics.
 The Analytics class has the following properties and methods.