[css-contain] Fix typo

Author: frivoal

css-contain-1/Overview.bs

@@ -413,7 +413,7 @@ Paint Containment</h3>
 		to access or indicate the presence of the clipped content;
 		nor does it inhibit the creation of any such mechanism through other properties,
 		<span class=informative>such as 'overflow', 'resize', or 'text-overflow'</span>.
-		<span class=note>This is as if to ''overflow: visible'' was changed to ''overflow: clip'' at used value.</span>
+		<span class=note>This is as if ''overflow: visible'' was changed to ''overflow: clip'' at used value.</span>
 	2. The element acts as a containing block for absolutely positioned and fixed positioned descendants.
 	3. The element creates a <a>stacking context</a>.
 	4. The element [=establishes an independent formatting context=].