ref: a8244658f74a7aabdd59dabf27df958bbe0eea45
dir: /docs/layouts/shortcodes/youtube.html/
<div class="video-container">
<iframe class="youtube-player" type="text/html" width="100%" height="auto" src="https://www.youtube.com/embed/{{ index .Params 0 }}" allowfullscreen frameborder="0">
</iframe>
</div>