add helper class for disabling all slide transitions

css/reveal.css

@@ -1041,7 +1041,8 @@ body {
           transform: none; }
 
 .reveal .no-transition,
-.reveal .no-transition * {
+.reveal .no-transition *,
+.reveal .slides.disable-slide-transitions section {
   transition: none !important; }
 
 /*********************************************

css/reveal.scss

@@ -1118,7 +1118,8 @@ $controlsArrowAngleActive: 36deg;
 }
 
 .reveal .no-transition,
-.reveal .no-transition * {
+.reveal .no-transition *,
+.reveal .slides.disable-slide-transitions section {
 	transition: none !important;
 }