Comment Out inline plugin, move to "external" folder inside project (same with loader).

[TheLarkInn]

Since there has been offered help to write a package test suite, I think it would be also great to teach developers who are writing these plugins and loaders how to write sturdy suites for them as well.

• Comment out inline plugin (its a little confusing for first time users anyways but I think should still be there).
• Plugin Suite
  • Move plugin to separate folder, with mono-repo style treatment, maybe even package.json
  • Add testing library (@sindresorhus 's ava would be fun since all async)
  • Write a few unit tests
  • Highlight ways to integration test with fixtures (actually running against a webpack build)
• Loader Suite
  • Move loader into separate folder, with mono-repo style treatment, maybe even package.json
  • Update resolveLoader.alias to reflect movement/location
  • Write a few unit tests
  • Highlight ways to integration test with fixtures (actually running against build)