Remove mentions of horizontal and vertical for touch navigation swipe gestures

Author: cderv

docs/presentations/revealjs/advanced.qmd

@@ -573,7 +573,7 @@ If your content benefits from vertical orientation (e.g. you have optional drill
 
 ## Touch Navigation
 
-You can swipe to navigate through a presentation on any touch-enabled device. Horizontal swipes change between horizontal slides, vertical swipes change between vertical slides.
+You can swipe to navigate through a presentation on any touch-enabled device. 
 
 If you wish to disable this you can set the `touch` option to `false`: