support for quarto

[jjallaire]

Hi there! Quarto is a new scientific markdown publishing system. It's based on pandoc and TLDR is a cross-language / cross-engine version of R Markdown. More details here: https://quarto.org

I noted that you already have built in support for both R Markdown and Julia Markdown. It would be great if you also automatically recognized quarto.

Here are the spellright settings for Quarto I have refined over about a week or so of writing and experimenting:

"spellright.documentTypes": ["quarto", "markdown", "latex", "plaintext"],
"spellright.parserByClass": {
    "quarto": {
      "parser": "markdown"
    }
},
"spellright.ignoreRegExpsByClass": {
    "quarto": ["/\\{.+\\}/", "/@[^ ]+/", "/\\n\\s*[^\\s\\:]+\\:/"]
}

The additional ignores are for the following scenarios:

1. /\{.+\\/ is for Pandoc attributes

2. "/@[^ ]+/ is for Pandoc citations

3. /\n\s*[^\s\:]+\:/ is for YAML keys

Would it be straightforward to add support for Quarto based on the above?