Meta: (re)export dfn for <link rel=serviceworker>

The way we did this in 5aa74a0 doesn’t actually make it possible to use
<{link/rel/serviceworker}> to create a cross-reference. But this does.

Author: sideshowbarker

source

@@ -23965,8 +23965,8 @@ interface <dfn>HTMLHyperlinkElementUtils</dfn> {
   the <code data-x="rel-search">search</code> link type to enable user agents to autodiscover search
   interfaces. <ref spec=OPENSEARCH></p>
 
-  <h5>Link type "<dfn data-dfn-for="link/rel" data-dfn-type="attr-value" data-export=""><code
-  data-x="rel-serviceworker">serviceworker</code></dfn>"</h5>
+  <h5 data-dfn-for="link/rel" data-dfn-type="attr-value" data-export="" data-lt="serviceworker">Link
+  type "<dfn><code data-x="rel-serviceworker">serviceworker</code></dfn>"</h5>
 
   <p>The <code data-x="rel-serviceworker">serviceworker</code> keyword may be used with
   <code>link</code> elements. This keyword creates an <span data-x="external resource link">external