Support JSON5 for .vscode/settings.json

[mrcjkb]

Feature description

See also #537.

Optionally, using https://github.com/Joakker/lua-json5.

It may be better to add basic JSON5 support (e.g. ignoring comments and trailing commas) to lua-cjson instead.

[b0o]

As a temporary workaround, I am overriding vim.json.decode with lua-json5 before loading rustaceanvim:

{
  'mrcjkb/rustaceanvim',
  version = '^5',
  ft = 'rust',
  dependencies = {
    {
      'Joakker/lua-json5',
      build = './install.sh',
      config = function()
        -- Support JSON5 syntax in .vscode/settings.json
        ---@diagnostic disable-next-line: duplicate-set-field
        vim.json.decode = function(str, _) return require('json5').parse(str) end
      end,
    },
  },
}