fix broken sticky about post link

index.html

@@ -33,7 +33,7 @@
     <div id="sticky-posts-section">
         <h2>Pinned posts</h2>
         <ul>
-            <li><a href="posts/about.html">About</a></li>
+            <li><a href="https://hexstudios.co/post.html?file=about.md">About</a></li>
         </ul>
     </div>