Add demo slides in scroll mode as example

docs/presentations/revealjs/presenting.qmd

@@ -116,6 +116,16 @@ You can enable Overview Mode by pressing the {{< kbd O >}} key.
 
 Reveal presentations can be presented in [Scroll View](https://revealjs.com/scroll-view/) with vertically scrolled navigation instead of Slides. This is a new view mode introduced in Revealjs 5. It is always available in presentations as an alternative view mode (like [Print view](#print-to-pdf)), and it will be used as the default view on small screens (e.g. viewing a presentation on a mobile).
 
+Our demo presentation can be seen [in scroll view mode](https://{{< meta prerelease-subdomain >}}quarto.org/docs/presentations/revealjs/demo/?view=scroll) and below
+
+<div>
+
+```{=html}
+<iframe class="slide-deck" src="demo/index.html?view=scroll"></iframe>
+```
+
+</div>
+
 ### Entering Scroll View {#scroll-view-toggle}
 
 To enter Scroll View , do one the following: