[css-text-decor] Update the link to Kenten Generic

Author: xfq

css-text-decor-3/Overview.bs

@@ -705,7 +705,7 @@ Emphasis Mark Style: the 'text-emphasis-style' property</h3>
 
   <p class="note">
       One example of good fonts for emphasis marks is Adobe's opensource project,
-      <a href="http://sourceforge.net/adobe/kenten-generic/">Kenten Generic OpenType Font</a>,
+      <a href="https://github.com/adobe-fonts/kenten-generic">Kenten Generic OpenType Font</a>,
       which is specially designed for the emphasis marks.
   </p>