feat(share-button): Basisstruktur der Klick-Aktion hinzugefügt

EnvelopeGenerator.Web/Views/Home/ShowEnvelope.cshtml

@@ -107,6 +107,14 @@
     <div id='app'></div>
 </div>
 <script nonce="@nonce">
+    document.addEventListener("DOMContentLoaded", function () {
+        const shareButton = document.querySelector('.dd-card-preview button');
+
+        shareButton.addEventListener('click', function () {
+            // click action logic
+        });
+    });
+
     const collapseNav = () => {
         document.addEventListener('click', function (event) {
             var navbarToggle = document.getElementById('navbarToggleExternalContent');