It’s not possible to embed videos directly, but you can put an image which links to a YouTube video: [](https://www.youtube.com/watch?v=YOUTUBE_VIDEO_ID_HERE) For more information about Markdown look at this Markdown cheatsheet on GitHub. For more information about Youtube image links look this question.
Each YouTube video has four generated images. They are predictably formatted as follows: https://img.youtube.com/vi/<insert-youtube-video-id-here>/0.jpg https://img.youtube.com/vi/<insert-youtube-video-id-here>/1.jpg https://img.youtube.com/vi/<insert-youtube-video-id-here>/2.jpg https://img.youtube.com/vi/<insert-youtube-video-id-here>/3.jpg The first one in the list is a full size image and others are thumbnail images. The default thumbnail image (i.e., one of 1.jpg, 2.jpg, 3.jpg) is: https://img.youtube.com/vi/<insert-youtube-video-id-here>/default.jpg For the high quality version of the thumbnail use a … Read more