Improve page with a more useful example

### Type of issue

Other (describe below)

### Description

Wouldn't it be more useful if you gave an example that users could actually use to make a fully functional right-click menu? Your example does not even demonstrate the use of commands, without which, the menu is useless.

### Page URL

https://learn.microsoft.com/en-us/dotnet/desktop/wpf/controls/contextmenu-overview?view=netframeworkdesktop-4.8

### Content source URL

https://github.com/dotnet/docs-desktop/blob/live/dotnet-desktop-guide/framework/wpf/controls/contextmenu-overview.md

### Document Version Independent Id

d91b3653-e5c2-a4f7-7a35-7e1c598e1319

### Article author

adegeo

### Metadata

* ID: 89a37173-c84e-a370-6d3d-f577e0ec9892
* Service: **dotnet-framework**
* Sub-service: **wpf**