Extract printers from `standalone` bundle

Now, standalone bundle includes printers for languages.

Ideally printers should be bundled as ./printers/*.js like parsers.

What do you think?

[sosukesuzuki]

To hard for user to use.

I know, but I think most standalone users will be concerned about bundle size. For standalone users, bundle size may be more important than ease of use.

[thorn0]

This reminded me of the AMD module format, bundlers know how to do that:

define(["doc"], (doc) => {
  // ...
});

This output is very close to what we need. Simply replace define with export default or module.exports = . 😃