Update link to documentation, to 0.13.0

Author: deanberris

index.html

@@ -111,7 +111,7 @@ <h1>Documentation</h1>
                                 <a href="0.12.0/index.html" class="btn btn-primary btn-lg btn-block">0.12.0 (stable)</a>
                             </div>
                             <div class="col-md-4">
-                                <a href="0.10.1/index.html" class="btn btn-danger btn-lg btn-block">0.10.1 (previous unsupported)</a>
+                                <a href="0.13.0/index.html" class="btn btn-danger btn-lg btn-block">0.13.0 (beta)</a>
                             </div>
                         </div>
                     </section>