create a general purpose copy mechanism like what is being used for assets/ directory copy

[thescientist13]

Type of Change

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

Summary

Not sure if this would just be a configuration like:

// _greenwood.config.js_
module.exports = {
  copy: [
    'some/path/a/',
    'some/path/b/,
  ]
}

Details

Something like the webpack plugin, and would be the same we would use internally as part of the build command.

[thescientist13]

Saw some "build shenanigans" related to copying files for the polyfills plugin, and in fairness / self deprecation, is a pretty inefficient way of copying these files, so this is me considering self-escalating the priority of this issue.