Allow static subset of jsx + some raw props

[RichiCoder1]

A variation on this plugin that manually walks the tree an converts "static" attributes and objects to the props object. Downside of this is you can't pass in the things like javascript variables (does MDX even support that?) but to enable that, we'd also need to a plugin for the HAST -> JSX that can handle those cases in a robust way.

[RichiCoder1]

For context, new output with the updated test.md looks like:

{
  "type": "root",
  "children": [
    {
      "type": "code",
      "lang": "jsx",
      "meta": "live startLine=1 forgivingString='string' title=\"test\" minHeight={100} style={{border: '1px solid red'}}",
      "value": "<Box>hello, world</Box>",
      "position": {
        "start": {
          "line": 1,
          "column": 1,
          "offset": 0
        },
        "end": {
          "line": 3,
          "column": 4,
          "offset": 141
        },
        "indent": [
          1,
          1
        ]
      },
      "props": {
        "live": true,
        "startLine": 1,
        "forgivingString": "string",
        "title": "test",
        "minHeight": 100,
        "style": {
          "border": "1px solid red"
        }
      }
    }
  ],
  "position": {
    "start": {
      "line": 1,
      "column": 1,
      "offset": 0
    },
    "end": {
      "line": 4,
      "column": 1,
      "offset": 143
    }
  }
}

[shawnbot]

Thanks for this, but I'm not looking for contributions at this point. This is very much a proof of concept for mdx-js/mdx#702, and after working through the static "evaluation" method I think that inserting the JSX props as-is (with support for key=value → key="value" conversion, for backwards compatibility) would be better.