Prepare ItemPage for MVVM light.
Add ItemPageViewModel.
Renamed all "Article" in MainViewModel to "Item".
Configured NavigationService.
Remove the "Windows Phone related" region from MainViewModel.
Implement NavigationService and openItemCommand in MainViewModel.
Fixed the openItemCommand.
Add Behaviours SDK to the Windows Phone references.
Make use of NavigationService.
Added binding for WebView on ItemPage.