Add Research link to footer (Linked Instant Messaging paper)

Author: melvincarvalho

index.html

@@ -330,6 +330,7 @@ <h2>Built on Open Standards</h2>
     <a href="/app">App</a>
     <a href="https://github.com/solid-chat">GitHub</a>
     <a href="https://solid.github.io/chat/">Spec</a>
+    <a href="https://melvincarvalho.github.io/webid.im/paper/">Research</a>
     <a href="https://solidproject.org">Solid Project</a>
   </div>
   <p>Made with ♥ for the decentralized web</p>