ref: bb1812b6af0ecd8fd064eb6f69289ddc8eb2c8e1
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>