Carousel Thumbnails: Use manually added HTML to reduce element flickering during creation.

[AlexanderMatveev]

Is your feature request related to a problem? Please describe.

I have a carousel with thumbnails at the top of the page. The problem is that at the moment of initialization the entire page flickers and moves from bottom to top, and I would like to get rid of this.

Describe the solution you'd like

Allow manually adding prerendered HTML and attach thumbs to it, just like Carousel https://fancyapps.com/carousel/getting-started/#usage:

<div class="f-thumbs f-carousel__thumbs is-classic is-ltr is-horizontal" id="carousel-thumbs">
    <div class="f-thumbs__viewport">
        <div class="f-thumbs__track" aria-live="polite">
            <!-- ... -->
        </div>
    </div>
</div>

Describe alternatives you've considered

No response

Additional context

No response