CollectionView separators - a teaser, we need more

### Type of issue

Missing information

### Description

[CollectionView](https://learn.microsoft.com/en-us/dotnet/api/microsoft.maui.controls.collectionview) does not include built-in separators. These can be provided, if desired, in the item template.

OK, but how? I'm off to find out, but I would argue that it is the documentation's responsibility to not just tease, but provide an answer / example, or link to something relevant.

### Page URL

https://learn.microsoft.com/en-us/dotnet/maui/user-interface/controls/collectionview/?view=net-maui-8.0

### Content source URL

https://github.com/dotnet/docs-maui/blob/main/docs/user-interface/controls/collectionview/index.md

### Document Version Independent Id

56821f6d-0cf1-2330-a905-1107313bc8dc

### Article author

@davidbritch

### Metadata

* ID: 56821f6d-0cf1-2330-a905-1107313bc8dc
* Service: **dotnet-mobile**
* Sub-service: **dotnet-maui**