Embedding DotnetFiddle in README.MD

I would like to be able to embed dotnet fiddle code snippet in my README.MD:
<iframe width="100%" height="475" src="https://dotnetfiddle.net/Widget/CsCons" frameborder="0"></iframe>
https://dotnetfiddle.net/Widget/Preview?url=/Widget/CsCons
It will allow readers to make experimental editions and run code right from the README.md.
Now, GitHub escapes iframe tags.

I’m afraid that GitHub’s HTML previewer for markdown (and all other supported markup syntaxes) will strip away any scripts, custom styles and non-basic HTML tags. So, even if you found a way to inject raw HTML code into your markdown, it won’t be rendered in the README preview (nor in any markdown doc preview on GitHub).

This is done for safety reasons.

The workaround is to use a more flexible lightweight markup syntax, like AsciiDoctor or pandoc markdown, and then convert the document to HTML and provide a Live HTML Preview links on your README:

https://htmlpreview.github.io/

which is the only way to allow users to preview HTML docs from GitHub.

Of course, you can just create an ordinary HTML document and link it that way too.

Beware that the Live HTML Preview service does block some scripts due to frames nesting, but it generally works fairly well — in some cases, I had to embed all the JS in the HTML doc, to ensure it was a fully standalone doc.

Ultimately, you might be better off just providing an external link to some third party service (i.e. directly to dotnet fiddle, in this case).