Syntax Highlighting Assistance

Description of the problem or steps to reproduce

I am unable to start a new Discussion, so I'm putting this in an issue. Which is sad because closing an issue relegates it to the garbage bin and a permanent place to get advice on creating syntax highlighting would be beneficial. Please correct me if such a place exists already.

Specifications

I'm attempting to create a syntax file for nushell configuration files (.nu). The Nushell Project has created a vscode (TextMate-based) syntax file which I'm using for reference.

However, there are some structural differences which I'm having problems with.

I'm trying to do Variables (identifier.var, I believe) and the existing syntax file has this:

"variable": {
  "match": "(alias|let|let-env)\\s+[\\$'\"]?([a-z A-Z0-9_-]+)['\"]?|(\\$[a-zA-Z0-9_\\-]+)|(\\|)([$a-zA-Z0-9-]+)[\\s,]+([$a-zA-Z0-9-]+)(\\|)",
  "name": "variable.nushell",
  "captures": {
    "1": { "name": "keyword.other.nushell" },
    "2": { "name": "variable.name.nushell" },
    "3": { "name": "variable.name.nushell" },
    "4": { "name": "punctuation.nushell" },
    "5": { "name": "variable.name.nushell" },
    "6": { "name": "variable.name.nushell" },
    "7": { "name": "punctuation.nushell" }
  }

How would I go about converting this to the YAML format? Am I breaking the "match" value into its component "captures" and naming them there?

Ultimately I'd like to have a script which converts from these common VSCode-compatible syntax files to Micro's YAML, although it is currently beyond my skillset and I'd require assistance.

Is anyone able to provide advice?

Commit hash: b9763856
OS: Windows
Terminal: Windows Terminal Preview

Start by comparing the referenced nushell.tmLanguage.json file with Micro's YAML syntax format, using commit b9763856 as the reported baseline. Determine whether the requested conversion guidance or a general conversion script is intended; done should provide a documented mapping for captures or a defined converter, but the issue does not name a target file or test.