chore: add footer with copyright

Author: molty3000

docs/index.html

@@ -53,6 +53,18 @@
 
     gtag('config', 'G-DHFKFCQFT3');
   </script>
+
+  <!-- Footer -->
+  <footer class="footer">
+    <div class="container">
+      <div class="social-links">
+        <a href="https://github.com/BackendStack21/fast-gateway" target="_blank">GitHub</a>
+        <a href="https://www.npmjs.com/package/fast-gateway" target="_blank">npm</a>
+        <a href="https://21no.de/" target="_blank">21no.de</a>
+      </div>
+      <p>Open source under the MIT License. © 2026 <a href="https://21no.de/">21no.de</a></p>
+    </div>
+  </footer>
 </body>
 
 </html>