Beta 5’s new video feature enables you to create instructional embeddable videos that travel with your playground. Yes, this means your playgrounds are going to be quite large — there is, as yet (despite requests to the contrary), no support for linking YouTube videos.
What you do is this, you add movie files to the playground’s resources. You can then add specialized playground rich text:
//: ![Alternate text](video width="width" height="height" poster="poster")
You won’t see the video until you render the rich text. The video below shows a tiny tutorial playground I created that uses embedded video to introduce its content.
p.s. To create this example, I had to build a playground, video myself using that playground, then embed that video in a playground, and video myself using the playground with the embedded video. After a while, it was just playgroundception, if you know what I mean.