Set of notification pseudo-markups created for GitHub upon the request @McFoggy in GitHub markdown issue. I used svg based rendered containers using the foreignObject trick. There are four of the notifications markup. I can add up upon request.

The only thing you have to do is to include them in your markdown file. An example below:

<img src="./markups/info-markup.svg">

The text inside them is predifined but you can change it easily just changing the span.message element in svg files. An example file is created in ./markdown folder. It is like below: