[clang-doc] Fix </section> mismatch in the namespace template

A `</section>` tag wasn't inside the `{{#HasRecords}}` Mustache tag, which caused a
mismatch if there weren't any records to render.

Author: evelez7

clang-tools-extra/clang-doc/assets/namespace-template.mustache

@@ -97,8 +97,8 @@
                             </li>
                         {{/Records}}
                         </ul>
-                    {{/HasRecords}}
                     </section>
+                    {{/HasRecords}}
                 </div>
             </div>
         </main>