Fix broken link

Also, I composed this description for important use-case for {{#markdown}}, but not sure how to put markdown in markdown in markdown:

The markdown block can also be used to continue parsing markdown content within an html tag that would normally not be processed as markdown:

```markdown
## My Header

Some more markdown

<div class='my class'>
{{#markdown}}
```js
//now my code will be pretty!
var a = 1 + 2;
`` //github choking on escaped 3rd tick
{{/markdown}}
</div>
```