add default user signatures

app/javascript/form.js

@@ -13,6 +13,7 @@ window.customElements.define('submission-form', class extends HTMLElement {
       authenticityToken: this.dataset.authenticityToken,
       canSendEmail: this.dataset.canSendEmail === 'true',
       isDirectUpload: this.dataset.isDirectUpload === 'true',
+      goToLast: this.dataset.goToLast === 'true',
       isDemo: this.dataset.isDemo === 'true',
       attribution: this.dataset.attribution !== 'false',
       withConfetti: true,