message: docs: add button type in form array example
  add a button type in the example of creating a dynamic form so that the button that adds the alias control does not submit the entire form
  PR Close
diff: <!-- #docregion formarrayname -->
  <div formArrayName="aliases">
  <h2>Aliases</h2>
  - <button (click)="addAlias()">+ Add another alias</button>
  + <button (click)="addAlias()" type="button">+ Add another alias</button>
  <div *ngFor="let alias of aliases.controls; let i=index">
  <!-- The repeated alias template -->
  