chore(docs): adjust getting started guide to DMN 1.3

related to CAM-11522

Author: marstamm

Diff for: layouts/index.html

@@ -37,7 +37,7 @@ <h2>Getting Started</h2>
             <a href="/get-started/cmmn11/">CMMN 1.1</a>
           </div>
           <div class="col-xs-6 col-md-4">
-            <a href="/get-started/dmn11/">DMN 1.1</a>
+            <a href="/get-started/dmn/">DMN 1.3</a>
           </div>
           <div class="col-xs-6 col-md-4">
             <a href="/get-started/spring/">Spring Framework</a>