fix: Add <dfn> for the [CEReactions] IDL extended attribute (#57)

Author: ExE-Boss

index.html

@@ -1674,6 +1674,7 @@ <h2>Dependencies</h2>
         <dfn><a href="https://www.w3.org/TR/html5/single-page.html#the-template-element">template</a></dfn>
     <li><dfn><a href="https://www.w3.org/TR/html5/single-page.html#void-elements">void elements</a></dfn>
     <li>The <a>template</a>'s <dfn data-lt="template content"><a href="https://www.w3.org/TR/html5/single-page.html#template-contents">template contents</a></dfn>
+    <li>The <dfn data-lt="CEReactions"><a href="https://www.w3.org/TR/html5/single-page.html#cereactios">[CEReactions]</a></dfn> IDL <a>extended attribute</a>
   </ul>
 
   The DOM specification [[!DOM4]] defines the following terms used in this document: