Markdown preview of HTTP with JSON body turns green

[gurksaften]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.87.1
• OS Version: Windows 10 Pro 22H2 64-bit

Steps to Reproduce:

1. Create a .md file with the following contents:

```http
HTTP/1.1 200 OK
Content-Type: application/json

{
	"ab": "a for abc abc a"
}
```

2. Open the preview of the the file and it will render the JSON strings as italic green (i assume comment-style).
   

3. Add a space between f and or in the word for in the body causes the rendering of the JSON to return to normal.
   

This seems to affect the entire body when the bug triggers causing all JSON strings to turn italic green unless you find the offending part of the JSON.

[Gobinath-B]

@mjbvz i want to work on this issue

[mjbvz]

This is an issue with highlight js we use in the preview. Switching to use VS Code's highlighting seems like the proper fix long term: #91279

[gurksaften]

Good job, @mjbvz, thank you. 👍