update "Who speaks what on GitHub?" link

index.html

@@ -171,7 +171,7 @@ <h2 id="resources"><a href="#resources">Research, visualizations, talks...</a></
             <li>
             <a href="http://githut.info/">GitHut</a> is an attempt to visualize and explore the complexity of the universe of programming languages.</li>
             <li>
-            <a href="http://danielvdende.com/gdc2014/">Who speaks what on GitHub?</a> Three visualizations provide insight into the language skills of users on GitHub.</li>
+            <a href="http://danielvdende.com/projects/gdc2014/index.html">Who speaks what on GitHub?</a> Three visualizations provide insight into the language skills of users on GitHub.</li>
             <li>
             <a href="http://blog.coderstats.net/github/2013/event-types/">GitHub in 2013</a> is a brief visual overview of GitHub event types in 2013.</li>
             <li><a href="http://geeksta.net/geeklog/exploring-expressions-emotions-github-commit-messages/">Exploring Expressions of Emotions in GitHub Commit Messages</a></li>