[css-text] Fix markup

Author: frivoal

css-text-4/Overview.bs

@@ -10640,7 +10640,7 @@ Interaction with Bidirectional Text</h4>
 			     RTL TEXT中国字
 			<p>一些中国字SOME RTL♥中国字.
 			<p>一些中国字<bdi dir=rtl>SOME RTL♥</bdi>中国字
-		</pre>
+		</xmp>
 
 		The expected rendering  ''ideographic-alpha'' would be something like