Fix discord link

Author: spuder

docs/_includes/footer_custom.html

@@ -3,11 +3,11 @@
         <ul>
             <li><a href="https://www.tindie.com/stores/spuder">Store</a></li>
             <li><a href="https://github.com/spuder/openspool">GitHub</a></li>
-            <li><a href="https://discord.gg/4EaXHu9CEj">Discord</a></li>
+            <li><a href="https://discord.gg/hphQsf8Rmx">Discord</a></li>
         </ul>
     </nav>
 
     <div class="footer-badge">
         <a href="https://www.tindie.com/stores/spuder/?ref=offsite_badges&utm_source=sellers_spuder&utm_medium=badges&utm_campaign=badge_small"><img src="https://d2ss6ovg47m0r5.cloudfront.net/badges/tindie-smalls.png" alt="I sell on Tindie" width="200" height="55"></a>
     </div>
-</footer>
+</footer>