[selectors-4] Export “document language”

Author: fantasai

selectors-4/Overview.bs

@@ -668,7 +668,7 @@ Data Model</h3>
 		and can't be matched by <em>any</em> <a>pseudo-class</a> except for '':host'' and '':host-context()''.)
 	</div>
 
-	Many of the selectors depend on the semantics of the <dfn>document language</dfn>
+	Many of the selectors depend on the semantics of the <dfn export>document language</dfn>
 	(i.e. the language and semantics of the document tree)
 	and/or the semantics of the <dfn>host language</dfn>
 	(i.e. the language that is using selectors syntax).