[css-contain-2] fix syntax error in note

Closes w3c#5506

Author: frivoal

css-contain-2/Overview.bs

@@ -164,7 +164,7 @@ Strong Containment: the 'contain' property</h2>
 			However, because it doesn't apply <a>size containment</a>,
 			the element can still respond to the size of its contents,
 			which can cause layout-invalidation to percolate further up the tree than desired.
-			Use ''contain: strict'' or ''contain: strict style'' when possible,
+			Use ''contain: strict'' or ''contain: size layout style paint'' when possible,
 			to gain as much containment as you can.
 
 		<dt><dfn>size</dfn>