shared-bulma-theme/layouts/shortcodes/imgs.html

<div class="columns is-img-preview">
    {{ range $param := .Params }}
    <!-- image -->
    {{ $items := split $param "|" }}
    {{ $src := (index $items 0) }}
    {{ $title := (index $items 1) }}
    {{ $split_src := split $src "." }}
    {{ $extension := index $split_src (sub (len $split_src) 1) }}
    <div class="column has-text-centered">
        {{ if eq $extension "mp4" }}
            <video preload="auto" autoplay="autoplay" muted="muted" loop="loop" webkit-playsinline="">
                <source src="{{ $src }}" type="video/mp4">
                Your browser doesn't support mp4 video. :(
            </video>
        {{ else }}
            <a href="{{ $src }}" title="{{ $title }}">
                <img src="{{ $src }}.jpg" alt="{{ $title }}">
            </a>
        {{ end }}
        {{ if $title }}
            <p class="has-text-centered is-italic has-text-grey-light">{{ $title }}</p>
        {{ end }}
    </div>
    {{ end }}
</div>