Need option to set tabindex of input element

[dockleryxk]

It would be great to be able to set the tabindex if needed. Currently, tabindex is always 0.

[dockleryxk]

If anyone else is waiting for the PR like me, a workaround is as follows in your component:

constructor(
    private renderer: Renderer2,
    @Inject(DOCUMENT) private document: any,
  ) { }

ngAfterViewInit() {
    // tabindex hack until ng2-flatpickr takes my PR
    this.renderer.setAttribute(this.document.getElementsByClassName('ng2-flatpickr-input flatpickr-input form-control input')[0], 'tabindex', 'tabindex-here');
  }