fix: broken link on homepage

Author: etabakov

build/_layouts/landing.html

@@ -144,7 +144,7 @@ <h3 class="start-links__title">NativeScript & Angular</h3>
                             <li><a href="/angular/ui/components">UI Widgets</a></li>
                             <li><a href="/angular/ui/layouts/layouts">Layouts</a></li>
                             <li><a href="/angular/app-and-screen-templates/app-templates">Application Templates</a></li>
-                            <li><a href="/angular/tooling/testing">Tooling</a></li>
+                            <li><a href="/angular/tooling/testing/testing">Tooling</a></li>
                             <li><a href="/angular/code-sharing/intro">Code Sharing</a></li>
                             <li><a href="/angular/ui/professional-ui-components/overview">NativeScript UI</a></li>
                         </ul>