message: allows to duplicate pages using a string as index
diff: @@ -202,7 +202,7 @@ export class Page extends Base {
  }
  /** Duplicate this page. Optionally, you can provide new data */
  - duplicate(index: number, data = {}): Page {
  + duplicate(index: number | string, data = {}): Page {
  const page = new Page({ ...this.src });
  page.parent = this.parent;
  page.dest = { ...this.dest };
  