[cssom-view] (editorial) fix bikeshed indent error

Author: zcorpan

cssom-view/Overview.bs

@@ -121,7 +121,7 @@ An element is <dfn>potentially scrollable</dfn> if all of the following conditio
 
 * The element has an associated <a>CSS layout box</a>.
 * The element is not <a>the HTML <code>body</code> element</a>, or it is and
-  the root element's used value of the 'overflow-x' or 'overflow-y' properties is not ''overflow/visible''.
+    the root element's used value of the 'overflow-x' or 'overflow-y' properties is not ''overflow/visible''.
 * The element's used value of the 'overflow-x' or 'overflow-y' properties is not ''overflow/visible''.
 
 Note: An element that is <a>potentially scrollable</a> might not have a <a>scrolling box</a>.