message: Add a description for itemComponent
diff: @@ -135,6 +135,9 @@ export class QuestionDropdownModel extends QuestionSelectBase {
  * Specifies whether to display a button that clears the selected value.
  */
  @property({ defaultValue: false }) allowClear: boolean;
  + /**
  + * The name of a component used to render drop-down menu items.
  + */
  @property() itemComponent: string;
  /**
  * Specifies whether to display a search bar in the drop-down menu.
  