Add coffee support section to encourage donations

Author: huycozy

index.html

@@ -199,6 +199,10 @@ <h2>Your network. Your data. Your control.</h2>
                 </div>
             </div>
         </section>
+
+        <div class="coffee-support" style="text-align: center; padding: 2rem 0; color: #a1a1aa;">
+            💙 If you liked this app, consider <a href="https://buymeacoffee.com/huynguyennovem" target="_blank" rel="noopener" style="color: #007bff; text-decoration: underline;">buying me a coffee</a>
+        </div>
     </main>
 
     <footer>