Add accessibility note on autoplaying content

[acnorrisuk]

As part of the WCAG guidelines, any auto-playing content lasting more than 5 seconds should be able to be paused or stopped by the user. https://www.w3.org/WAI/WCAG21/Understanding/pause-stop-hide.html

As the autoPlay setting is optional, it's worth adding a note to let people know that this can cause issues for users.

An example of this might be someone with a vestibular disorder. https://alistapart.com/article/accessibility-for-vestibular/