[css-containment] Fixup based on code review.

Author: frivoal

css-containment/Overview.bs

@@ -153,12 +153,12 @@ Layout Containment</h3>
 		then they are not generated.
 		If they would exist regardless,
 		they remain part of the <a>fragmentation context</a>,
-		but do no receive any content from the <a>fragmented flow</a>.
+		but do not receive any content from the <a>fragmented flow</a>.
 
 		Specifically:
 			- <a spec=css-regions>CSS Regions</a> following the one which traps the content
 				are still considered part of the <a spec=css-regions>region chain</a>
-				as returned by the {{getRegions()}} method
+				as returned by the {{NamedFlow/getRegions()}} method
 				of the {{NamedFlow}} interface.
 			- the {{regionOverset}} attribute of the {{Region}} interface
 				of the region which traps the content