Add Multiselektionspulldown pattern based on form sections structure

index.html

@@ -45,6 +45,7 @@
         <li><a href="./patterns/object-group-card.html">Object Group Card</a></li>
         <li><a href="./patterns/navigation-card.html">Navigation Card</a></li>
         <li><a href="./patterns/content-cards-group.html">Content Cards Group</a></li>
+        <li><a href="./patterns/multiselektionspulldown.html">Multiselektionspulldown</a></li>
         <li><a href="./patterns/card-gruppe-mit-tastennavigation.html">Card Gruppe mit Tastennavigation</a></li>
         <li><a href="./patterns/formular-mit-abschnitten.html">Formular mit Abschnitten</a></li>
       </ul>