Fix typo

Author: Psychpsyo

css-view-transitions-1/Overview.bs

@@ -1384,7 +1384,7 @@ urlPrefix: https://wicg.github.io/navigation-api/; type: interface;
 			1. Set |capture|'s [=old image=] to the result of [=capturing the image=] of |element|.
 
 			1. Let |originalRect| be [=snapshot containing block=] if |element| is the [=document element=],
-				otherwise, the element|'s [=border box=].
+				otherwise, the |element|'s [=border box=].
 
 			1. Set |capture|'s [=captured element/old width=] to |originalRect|'s {{DOMRect/width}}.