Add feedback from i18n W3C review.

Fixes #151

index.html

@@ -306,6 +306,22 @@ <h2>
             being used in a 'laptop' posture.
             </li>
           </ul>
+          <div class="note">
+            <p>When a foldable is used in a half-folded state (like a book), 
+              implementers might need to take into account the effect of
+              text direction and writing mode on the layout and presentation.
+
+              <p>For example, right-to-left languages 
+                (those that use scripts such as Arabic, Hebrew, Syriac, and others) 
+                and many vertical writing modes used by, for example, East Asian languages
+                progress pages in the opposite order to that used by an English book, 
+                with the lower numbered page on the right.
+              </p>
+              See <a data-cite=
+              "clreq#major_differences_between_horizontal_and_vertical_writing_modes">Chinese</a>,
+              <a data-cite=
+              "jlreq#major_differences_between_horizontal_and_vertical_writing_modes">Japanese</a>,
+              and <a data-cite="klreq/#para-diffs">Korean</a> differences in writing modes for more information.</p>
         </li>
       </ol>
       <p>