[css-writing-modes-3] Update Changes list.

Author: fantasai

css-writing-modes-3/Overview.bs

@@ -2553,6 +2553,18 @@ Privacy and Security Considerations {#priv-sec}
 
 <h2 class="no-num" id="changes">Changes</h2>
 
+  <h3 class="no-num" id="changes-201712">
+  Changes since the <a href="http://www.w3.org/TR/2015/CR-css-writing-modes-3-20171207/">December
+  2017 CSS Writing Modes Module Level 3 Candidate Recommendation</a></h3>
+
+  <ul>
+    <li>Fixed the fallback “available space” for orthogonal flows
+        to handle 'max-height' (and 'min-height') which it forgot to consider.
+        (<a href="https://github.com/w3c/csswg-drafts/issues/2239">Issue 2239</a>)
+    <li>Clarified the <a href="#bidi-fragmentation">conditions for bidi reordering-induced fragmentation</a>.
+        (<a href="https://github.com/w3c/csswg-drafts/issues/1509">Issue 1509</>)
+  </ul>
+
   <h3 class="no-num" id="changes-201512">
   Changes since the <a href="http://www.w3.org/TR/2015/CR-css-writing-modes-3-20151215/">December
   2015 CSS Writing Modes Module Level 3 Candidate Recommendation</a></h3>