Fix up a missing section (#312)

* [chore] Fix up tidy errors

* chore: tidy up index.html

* Fix up a missing section end

* Remove leftovers

Co-authored-by: yoavweiss <yoavweiss@users.noreply.github.com>

index.html

@@ -1122,6 +1122,7 @@ <h2>
           HTTP response header, which specifies the domains that are allowed to
           access the timing information.
         </p>
+      </section>
       <section id="sec-privacy" class='informative'>
         <h2>
           Privacy Considerations