message: docs(aio): fix host usage in styleguide
diff: @@ -4,7 +4,7 @@ import { Directive } from '@angular/core';
  @Directive({
  selector: '[tohValidator2]',
  host: {
  - 'attr.role': 'button',
  + '[attr.role]': 'role',
  '(mouseenter)': 'onMouseEnter()'
  }
  })
  