Add a More-button for collapsing the list after the first horizontal ruler

static/js/wishlists.js

@@ -97,6 +97,16 @@ function updateListHTML(listElem) {
     $("ul > li", listHtmlElem).has('input[type="checkbox"]')
                               .parent()
                               .addClass("tasklist");
+    if (listHtmlElem.find('hr').length) {
+      listHtmlElem.find('hr')
+                  .nextAll()
+                  .wrapAll('<div class="collapse list-more"/>')
+      listHtmlElem.append('<div class="row justify-content-center">' +
+        '<button class="btn btn-sm btn-light text-dark" data-toggle="collapse" ' +
+                 'data-target=".list[data-list-id=\'' + listId + '\'] .list-more">' +
+          'Meer…</button>' +
+        '</div>');
+    }
   }).fail(function(html, textMsg, error) {
     listHtmlElem.html("<h3><i>Kan lijst niet tonen!</i></h3>" +
       "<p class='pt-2'><small><i>(Technische foutmelding: " + error +