Added PowerPoint templates to the Slide Assistant (#1055)

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

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

@@ -0,0 +1,8 @@
+namespace AIStudio.Tools.PowerPoint;
+
+/// <summary>
+/// What one slot of a template slide holds.
+/// </summary>
+/// <param name="Slot">The slot, as the layout of the slide offers it.</param>
+/// <param name="Text">The text, one paragraph per line; empty for a picture. A table gives one row per line, with " | " between its cells.</param>
+internal sealed record TemplateSlideContent(TemplateSlot Slot, string Text);