index: fix link to fragment serializing algorithm (#1397)

Author: JohnChen0

index.html

@@ -9301,7 +9301,7 @@ <h2>Index</h2>
  <dt>DOM Parsing
  <dd><p>The following terms are defined in the DOM Parsing and Serialization Specification: [[!DOMPARSING]]
   <ul>
-   <li><!-- Fragment serializing algorithm --><dfn><a href="https://w3c.github.io/DOM-Parsing/#dfn-fragment-parsing-algorithm">Fragment serializing algorithm</a></dfn>
+   <li><!-- Fragment serializing algorithm --><dfn><a href="https://w3c.github.io/DOM-Parsing/#dfn-fragment-serializing-algorithm">Fragment serializing algorithm</a></dfn>
   </ul>
  </dd>