add IOCCC markdown to the About menu

bugs.html

@@ -179,6 +179,12 @@
                 Thanks for the help
               </a>
             </div>
+
+            <div class="outfit-font">
+              <a href="./markdown.html" class="sub-item-link">
+                IOCCC markdown
+              </a>
+            </div>
           </div>
         </div>
       </div>