message: chore(demo): change input to btn for supporting one demo standart
diff: <input placeholder="Datepicker" type="text" class="form-control" bsDatepicker #dp="bsDatepicker">
  </div>
  <div class="col-xs-12 col-12 col-sm-4 col-md-12 col-lg-4 form-group">
  - <input type="button"
  - class="btn btn-success"
  - value="Date Picker"
  - (click)="dp.show()" />
  + <button class="btn btn-success" (click)="dp.show()" [attr.aria-expanded]="dp.isOpen">Date Picker</button>
  </div>
  </div>
  <br>
  <input placeholder="Daterangepicker" type="text" class="form-control" bsDaterangepicker #dpr="bsDaterangepicker">
  </div>
  <div class="col-xs-12 col-12 col-sm-4 col-md-12 col-lg-4 form-group">
  - <input type="button"
  - class="btn btn-success"
  - value="Date Range Picker" (click)="dpr.show()"/>
  + <button class="btn btn-success" (click)="dpr.show()" [attr.aria-expanded]="dpr.isOpen">Date Range Picker</button>
  </div>
  </div>
  -
  