Add context option to gatsby-transformer-javascript-frontmatter

[emilfjellstrom]

Hi,

Would it be possible to add a context option to gatsby-transformer-javascript-frontmatter?

This would be useful when querying allSitePages and being able to get context from both MDX file as well as jsx|tsx.

Since the plugin already collects the data from the file in text and putting it in the schema there must be a way to also place it in the context?

So that this

export const frontmatter = {
  title: 'About',
  path: '/about',
  isIndexable: true,
}

Is listed in here

{
  "data": {
    "allSitePage": {
      "nodes": [
        {
          "path": "/about",
          "context": {
            "frontmatter": {
              "title": "About"
              "path": "/about",
              "isIndexable": true,
            }
          }
        }
      ]
    }
  }
}

Along with all the other MDX file that has frontmatter context