Add Page to ViewModel Binding in ReactiveUI

[RLittlesII]

Under docs/handbook/routing/ we should add the following nodes that explain ReactiveUI's platform specific registrations.

This should cover the following:

• [x] View/ViewModel registration for Routing

• [ ] Reactive Controls and Control<ViewModel> binding and creation

• [ ] View Fetching Activation from ViewModel

• [ ] View Model Bindable Property

• [x] RoutingState

• [x] RoutedViewHost

[worldbeater]

Here is an excellent blog post explaining Xamarin.Forms & ReactiveUI routing https://jamilgeor.com/viewmodel-routing-with-reactiveui-and-xamarin-forms/ Might be worth referencing it.

Jamil Geor

ViewModel Routing with ReactiveUI and Xamarin.Forms

Introduction In this article we will cover how to navigate from one view to another, using ReactiveUI routing. For our example, we will allow the user to select an article from our article list, which in turn will navigate to the article detail view. Setup In this article, we are