Add internationalization section (w3c#452)

Author: szager-chromium

index.bs

@@ -14,6 +14,7 @@ Group: webapps
 Repository: W3C/IntersectionObserver
 Test Suite: http://w3c-test.org/intersection-observer/
 Ignored Vars: rootMargin, docs, now
+Markup Shorthands: markdown yes
 </pre>
 
 <pre class="anchors">
@@ -776,6 +777,14 @@ which has privacy and security considerations of its own. It is however unlikely
 at most once per rendering update (see [[#event-loop]]), which is far too
 infrequent for the familiar kind of timing attack.
 
+<!-- ============================================================ -->
+<h2 id=internationalization>Internationalization</h2>
+<!-- ============================================================ -->
+
+*This section is non-normative.*
+
+There are no known issues concerning internationalization.
+
 <!-- ============================================================ -->
 <h2 id=acknowledgements>Acknowledgements</h2>
 <!-- ============================================================ -->