TIL: Using backticks in highlighted code

If you want to use code fences in a highlighted block of code in a (Github-flavoured) Markdown document you cannot just use code fences themselves to highlight the code.

Instead you have to use three tildes like this:

~~~html
```
<script src="foobar.js"></script>
```
~~~

This will then look like this:

```
<script src="foobar.js"></script>
```

I have used this both in hugo and jekyll.