Switch to side-by-side view

--- a/website/CHANGES.html
+++ b/website/CHANGES.html
@@ -33,7 +33,12 @@
 
       <p>Newer releases are described in their release notes document:</p>
       <p>
-         <a href="release-1.16.html">(future)1.16</a> 
+         <a href="release-1.21.html">1.21</a> 
+         <a href="release-1.20.html">1.20</a> 
+         <a href="release-1.19.html">1.19</a> 
+         <a href="release-1.18.html">1.18</a> 
+         <a href="release-1.17.html">1.17</a> 
+         <a href="release-1.16.html">1.16</a> 
          <a href="release-1.15.html">1.15</a> 
          <a href="release-1.14.4.html">1.14.4</a>
        </p>