[css-contain-2][editorial] fix markup

Author: tabatkins

css-contain-2/Overview.bs

@@ -1496,14 +1496,14 @@ Restrictions and Clarifications {#cv-notes}
     happen in the same frame that determined an existence of a new
     ''content-visibility: auto'' element.
 
-  <div class=note>
-    When an element first gains ''content-visibility: auto'', it may or may not
-    be positioned on screen. The determination of this state and thus
-    determination of whether this element is [=skipped=] must happen in the
-    same frame. If it does not, then there is a possibility of producing blank
-    content in the element's place since visibility check and [=skipped=] state
-    update would be deferred to the next frame.
-  </div>
+	<div class=note>
+		When an element first gains ''content-visibility: auto'', it may or may not
+		be positioned on screen. The determination of this state and thus
+		determination of whether this element is [=skipped=] must happen in the
+		same frame. If it does not, then there is a possibility of producing blank
+		content in the element's place since visibility check and [=skipped=] state
+		update would be deferred to the next frame.
+	</div>
 
 5. For the purposes of scrolling operations,
 	such as {{Element/scrollIntoView()}},