message: Add description for useGrouping property in expression
diff: @@ -118,6 +118,9 @@ export class QuestionExpressionModel extends Question {
  if (getCurrecyCodes().indexOf(val) < 0) return;
  this.setPropertyValue("currency", val);
  }
  + /**
  + * Determines whether to display grouping separators. The default value is true.
  + */
  public get useGrouping(): boolean {
  return this.getPropertyValue("useGrouping", true);
  }
  