try to add duplicate warning definition only for knitr

[cderv]

In knitr, warning: 'NA' is supported. How to allow that for auto completion ?

---
title: "test"
format: html
---

```{r}
#| warning: NA
warning("Test")
```

[cderv]

@cscheid Do you know if our schema would allow to get a specific YAML validation for an option in cell

while this option is also used as document-execute.

The way I tried here, seems to have remove the execute part

while correctly added under cell

Normaly warning is also in execute

So do we have a way to have two warning definition with our schema ?

Thank you !

[cderv]

A note that the document in example

---
title: "test"
format: html
---

```{r}
#| warning: NA
warning("Test")
```

Is not supposed to be rendered and should have a validation error at rendering time.

But this is not happening because of

quarto-cli/src/core/schema/validate-document.ts

Lines 113 to 116 in 46d71b0

	const fullCell = mappedString(cell.sourceVerbatim, [{
	start: lang.length + 6,
	end: cell.sourceVerbatim.value.length - 3,
	}]);

End line problem 😁 \r\n on Windows, so start should be + 7 not 6.

Fixing this will probably make a lot of document fails, at least those using valid knitr option but unknown to validation. We'll see.

I'll probably open a new PR to solve this issue.