Redo the feed display with Avalonia rich text

[hhyyrylainen]

Looks like the 11 version of avalonia now has very good features like:

Full Rich Text support You can now fully render rich text allowing you to render complex documents

With the Text Inlines feature, you can easily construct complex formatted text blocks. It enables you to add annotations, hyperlinks, and other inline elements in your text.

[hhyyrylainen]

Turns out this is a "document" feature but it is missing support for hyper links: AvaloniaUI/Avalonia#10186 (AvaloniaUI/Avalonia#8818)

Some further reading which should help when the text block inlines support hyperlinks for implementing this:

• Inherit from Inline AvaloniaUI/Avalonia#9076
• TextBlock Inlines Binding AvaloniaUI/Avalonia#7972
• https://stackoverflow.com/questions/1959856/data-binding-the-textblock-inlines
• 11.0.0 AvaloniaUI/Avalonia#12039 (comment)
• Add TextBlock inlines support AvaloniaUI/Avalonia#6953