adjust form templates

app/javascript/submission_form/completed.vue

@@ -41,6 +41,14 @@
         </span>
       </button>
     </div>
+    <div class="text-center mt-4">
+      Signed with
+      <a
+        href="https://www.docuseal.co"
+        target="_blank"
+        class="underline"
+      >DocuSeal</a> - open source documents software
+    </div>
   </div>
 </template>