Mdpad - one-file web apps

I’ve been putting together a reasonably simple way to create web apps with Markdown and simple JavaScript:

It works great with Hugo. The best way to get a sense of how it works is with JS-Bin where you can see the input and output: example1, example2.

I’ve also experimented with Shortcodes to generate form inputs.

Hopefully, this isn’t too off topic. I’d love to hear about ideas for this or good JS libraries for this type of app.