TipCalc Tutorial - Missing Attributes in tutorial-documentation
## 🐛 Bug Report

The following Attribute-Tags are not mentioned in the Tutorial (missing in TipView.xaml.cs)
`[MvxContentPresentation]`
`[MvxViewFor(typeof(TipViewModel))]`

Without them there's only a white window visible.

### Expected behavior

TipView should be displayed, whenever TipViewModel is visible.
Change in documentation needed.

### Reproduction steps

Following the tutorial.

### Configuration

**Version:** 8.0.2

**Platform:** 
- [ ] :iphone: iOS
- [ ] :robot: Android
- [X] :checkered_flag: WPF
- [ ] :earth_americas: UWP
- [ ] :apple: MacOS
- [ ] :tv: tvOS
- [ ] :monkey: Xamarin.Forms
