message: docs(modal): fix angular card modal example
diff: </ion-header>
  <ion-content class="ion-padding">
  <ion-button id="open-modal" expand="block">Open</ion-button>
  - <ion-modal #modal trigger="open-modal" [swipeToClose]="true" [canDismiss]="canDismiss">
  + <ion-modal #modal trigger="open-modal" [swipeToClose]="true" [canDismiss]="canDismiss" [presentingElement]="presentingElement">
  <ng-template>
  <ion-header>
  <ion-toolbar>
  