[Feature request]: `<details>` support

[nenadalm]

Hi. I was thinking about showing some collapsible source code and found that it can be done using markdown: https://gist.github.com/pierrejoubert73/902cc94d79424356a8d20be2b382e1ab#gistcomment-2705100

In devcards, it doesn't work with code blocks though.

This works (hidden text is visible only after clicking the arrow):

<details>
<summary>Source</summary>
hidden text
</details>

This doesn't work (code block is not inside details element anymore in DOM):

<details>
<summary>Source</summary>
```clojure
(prn \"hello\")
```
</details>