Here’s a command line based Node.js based tool allowing you to easily create neatly formatted playgrounds using Markdown called the Swift Playground Builder from Jason Sandmeyer.
The tool allows you to specify the oath and file locations for building the playground, and then the playground is automatically created. Jason has set up an online builder over on his site.
Here’s an image from the readme showing a playground formatted with the Swift playground builder:
You can download the Swift Playground Builder on Github here.