Gatsby object expander

This takes documents and expands them - very useful in conjunction with the json loader to simulate a cms

If the json structure has a type and module field, the type is used to generate the new node type using the contents of the module object for the contents

e.g.

{
    "type": "Component 1",
    "module": {
        "title": "This is component 1",
        "messages": [
            "Message 1",
            "Message 2"
        ]
    }
}

It produces the graphql objects 'docComponent1' with the contents

{
    "title": "This is component 1",
    "messages": [
        "Message 1",
        "Message 2"
    ]
}

Example usage

    {
      resolve: "gatsby-source-filesystem",
      options: {
        name: "docs",
        path: "./docs/",
      },
      __key: "docs",
    },
    "gatsby-transformer-json",
    {
      resolve: "@bond-london/gatsby-transformer-expand",
      options: {
        sourceType: "DocsJson",
        typeField: "type",
        moduleField: "module",
        unNest: 2,
      },
    },

This would take the output from the docs folder, transform using json, expand out entries with a type and module field, creating a parent child relationship from the original json file to the new object