[css-view-transitions-1] index.html required in link for some reason

Author: jakearchibald

css-view-transitions-1/Overview.bs

@@ -176,7 +176,7 @@ urlPrefix: https://html.spec.whatwg.org/multipage/rendering.html; type: dfn;
 
 	<div id="phases-diagram">
 		<spec-scaler canvaswidth="1920" canvasheight="1080" style="aspect-ratio: 1920/1080">
-			<iframe class="spec-slides" src="diagrams/phases/"></iframe>
+			<iframe class="spec-slides" src="diagrams/phases/index.html"></iframe>
 		</spec-scaler>
 		<p class="spec-slide-controls">
 			<button disabled>Previous</button>