I've published a new Micro.blog plugin called Lite YouTube which does one thing: finds YouTube links in posts and appends a lite-youtube-embed to the post. Example before and after below:
You can see it working on this post about The Last of Us or on this post with two videos.
Why did I do this instead of using YouTube shortcodes? Two reasons:
You can install it from the plug-in directory and view the code on GitHub.