@parkproject, @Jeanne it is now possible to embed videos in description fields. You need to use the {iframe src="..."} format.
For example, in a Youtube videos share page, you get this code:
<iframe width="560" height="315"
src="https://www.youtube.com/embed/z7VYVjR_nwE" frameborder="0"
allow="autoplay; encrypted-media"
allowfullscreen></iframe>
You need to take the src= part and transform it like this:
{iframe src="https://www.youtube.com/embed/z7VYVjR_nwE"}
I created a map to demonstrate it here: https://maphub.net/hyperknot/video-embed
You can read more about it in this blog post: