Add Youtube Video in AMP

<!-- JavaScript Google AMP -->

<script async='async' custom-element='amp-youtube' src='https://cdn.ampproject.org/v0/amp-youtube-0.1.js'/>

youtube.com/watch?v=xxxxxxxxxxx

<amp-youtube width='480' height='270' layout='responsive' data-videoid='xxxxxxxxxxx'></amp-youtube>

<amp-youtube width='480' height='270' layout='responsive' data-videoid='xxxxxxxxxxx' autoplay='autoplay'></amp-youtube>