chore(CHANGELOG): add reasons for breaking changes

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 #### Ionic Decorators Removed
 
+We’ve started the process of optimizing Ionic 2 to improve our support for Progressive Web Apps. Because of this, we have removed the Ionic decorators in favor of using Angular's `Component` decorator. The following changes need to be made. For a step by step guide, see the [Steps to Upgrade to Beta 8 section](https://github.com/driftyco/ionic/blob/2.0/CHANGELOG.md#steps-to-upgrade-to-beta-8).
+
 - `@App` and `@Page` should be replaced with `@Component`.
 - `IonicApp` has been renamed to `App`.
 - `ionicBootstrap` is required to bootstrap the app.
@@ -15,6 +17,8 @@
 
 #### Ionic Lifecycle Events Renamed
 
+All Ionic lifecycle events have been renamed from starting with `onPage` to starting with `ionView`. These changes were made to make it more clear that the events belong to Ionic on each view.
+
 - `onPageLoaded` renamed to `ionViewLoaded`
 - `onPageWillEnter` renamed to `ionViewWillEnter`
 - `onPageDidEnter` renamed to `ionViewDidEnter`