Missing example implementation of Windows notification manager service

### Type of issue

Missing information

### Description

The article describes a setup of cross-platform notifications. Everything necessary is included in the article except an example implementation of the INotificationManagerService for Windows. Instead the implementation section links to a different article, which is very complex, uses C++ code and works with a completely different setup (i.e. not .NET MAUI). The sample code in the Github repository also does not contain the Windows implementation.

Motivation: cross-platform notifications are a basic feature which should be super easy to setup. I am new to .NET MAUI and was not able to set this up based on the information provided in the article.

### Page URL

https://learn.microsoft.com/en-us/dotnet/maui/platform-integration/local-notifications?view=net-maui-8.0&pivots=devices-windows#create-a-cross-platform-abstraction

### Content source URL

https://github.com/dotnet/docs-maui/blob/main/docs/platform-integration/local-notifications.md

### Document Version Independent Id

a60fefdf-9ad0-349e-6ef2-7ff806a9bf6a

### Article author

@davidbritch

### Metadata

* ID: a60fefdf-9ad0-349e-6ef2-7ff806a9bf6a
* Service: **dotnet-mobile**
* Sub-service: **dotnet-maui**