have a plugin for being able to import JSON using ESM

[thescientist13]

Type of Change

• New Feature Request
• Documentation / Website
• Improvement / Suggestion
• Bug
• Other (please clarify below)

Summary

As is the case with CSS, being able to use import with JSON is against the spec, and so this sort of behavior should be moved into a plugin, instead of being supported by default by the CLI.

Details

Currently this is supported by default but shouldn't be so we should extract this code into a standalone package; plugin-import-json.

const json = await fs.promises.readFile(url, 'utf-8');

contentType = 'text/javascript';
body = `export default ${json}`;

I don't know if this will have any impact on just using fetch for .json so should just do some basic sanity checking. This plugin will then need to be added to greenwood.config.js

[thescientist13]

Started a discussion for this here - #606