How can I use highlighting props on fence?

[buhodev]

Is your feature request related to a problem? Please describe.
I got markdoc + shiki working. However, I couldn't find a way to use {} syntax for highlighting

Describe the solution you'd like
Is it possible to pass this string as a prop on the fence component? (in this case is {1-2,4} next ot the lang prop)

```js {1-2,4}
console.log('hello');
console.log('world');

let number = 42;
```

I already have a custom fence component, but I couldn't manage to pass another variable or prop next to the lang prop

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context

Here's an example of how to add code highlighting from markdoc docs

[TorstenDittmann]

I dont think markdoc supports this syntax as of right now 🤔

[TorstenDittmann]

Actually it is possible => markdoc/markdoc#480 (comment)

But the preprocessor only allows the default attributes right now, so this will result in an error for now.