### Is your feature request related to a problem? Please describe... I am building a custom datepicker based on the calendar component which requires that when tabbing through inputs, focus not be shifted to the calendar but rather to the next input. ### Describe the solution you'd like Expose a new parameter for b-calendar, `tabindex` with a default value of 0 ### Describe alternatives you've considered Manually updating tabindex values rendered by the component on mount, jquery style. Unpleasant and anti-pattern. ### Additional context As added value, this feature can solve problems for people with complex tab layouts ( layouts that call for more than just -1 and 0 values )