Add Xibo Embedded YouTube template
Add Xibo Embedded YouTube template

Original source from the Xibo Community hub:
- https://community.xibo.org.uk/t/autoplay-embedded-youtube-videos/5228

Modified with these changes:
* [CSS] Set page margins and paddings to none (0)
* [CSS] Disable pointer events for page
* [JS] Set the player size to the current document size
* [JS] Hide player controls
* [JS] On Player Ready mute the sound and reduce the playback rate by
  0.5 (the video was a bit too fast on the Android Display Client)
* [JS] Add On Player State change listener - destroy the player when
  playback has finished

alni/digital-signage-samples,alni/digital-signage-samples,alni/digital-signage-samples