Add changelog page

Author: RascalTwo

website/index.html

@@ -9,6 +9,7 @@
     <nav>
       <ul>
         <li><a href="./tai-chad-allen.html">Draft Plan Strategy & Class One Cohort Two Content</a> by Chad Allen</li>
+        <li><a href="./changelog.html">Changelog</a></li>
       </ul>
     </nav>