I think I've found a bug in nearly every #Markdown parser.
Most of them will autolink URls.
But consider this:
```
<a href="https:/example.com">You *must* visit https:/example.com</a>
```
You'll get back:
```
<a href="https:/example.com/">You <em>must</em> visit <a href="https:/example.com">https:/example.com</a></a></p>
```
All the Markdon inside the <a> - including the link - is processed.
The HTML is invalid; you can't nest <a>s like that.
Bug or not?