Generate routes from static *.md files

Sometimes you need to have a list of static pages written in Markdown. E.g. blog posts:

/posts/first-entry.md
/posts/second-entry.md

It would be nice to automatically generate routing information for these pages during build, as well as convert them into React components. For example, with Webpack 2.x syntax such automatically generated routes may look like this:

{
  path: '/blog/first-entry',
  load: function() {
    System.import('./posts/first-entry.md').then(function (data) {
      return <PostLayout><Content {...data} /></PostLayout>;
    });
  }
}

This was the core feature of the boilerplate, but was removed during a major refactoring. Would you like to bring it back? It requires adding more logic into the utils/routes-loader.js file.

Start with utils/routes-loader.js and inspect how the current build creates routing information. Compare its behavior with the Markdown examples in the issue; done means static .md pages produce generated routes and React components during the build.