`code-fold` for non executable code

Discussed in https://github.com/quarto-dev/quarto-cli/discussions/4558

^{Originally posted by rleyvasal February 28, 2023}
It would help presenters to have the ability to highlight code and also do code-fold when the code is only for demonstration in a language non executable such as scss.

At the moment code in R, Python, can use code-fold but if other languages are in a code block which is only highlighted, then the code is not fold-able.

Python code is foldable with code-fold but scss highlighted is not foldable as seen below:

Reproducible Code

---
title: "My document"
format:
  html:
    code-fold: true
    code-summary: "Show code"
---

```{python}
#| eval: false

// Content.scss
@use 'colors' as colors;
body > content {
    padding: 40px;
    margin: auto;
    max-width: 100%
}
```


Show code below folded

```scss
// Content.scss
@use 'colors' as colors;
body > content {
    padding: 40px;
    margin: auto;
    max-width: 100%
}
```

Related

• https://github.com/quarto-dev/quarto-cli/discussions/3426
• https://github.com/quarto-dev/quarto-cli/discussions/12907