Added PowerPoint templates to the Slide Assistant (#1055)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Tools/PowerPoint/SlideTextBlock.cs

@@ -0,0 +1,7 @@
+namespace AIStudio.Tools.PowerPoint;
+
+/// <summary>
+/// The content of one text slot.
+/// </summary>
+/// <param name="Paragraphs">The paragraphs, in order.</param>
+internal sealed record SlideTextBlock(IReadOnlyList<SlideParagraph> Paragraphs);