feat: Implement default configuration where possible

[phated]

This was a random idea I had while working on this package. Why do we require people to configure their require hooks? We can (mostly) do that for them when we load the hook. Many of the hooks I researched allow you to pass any options when calling the register function.

This PR demonstrates the things we could override by default. Looking for thoughts about the overall idea.

[phated]

@sttk what do you think of this approach? Will it cause users to be confused?

[sttk]

@phated I forget the inside of interpret and rechoir, and try to remember them now. Please wait for a while.

[sttk]

@phated I think that this is good idea, but I'm worried that there are no way that user changes this default configuration because it is inside a function.
How about adding a new property to specify this options, and merging it in a function? (Though this needs to modify rechoir.)

var extensions = {
  '.babel.js': {
    module: '@babel/register',
    register: function (hook, overrides) {
      hook({
        extensions: '.js',
        rootMode: 'upward-optional',
        // MODIFY: Merge configurations with excluding necessary options.
        overrides: [defaults({ only: [endsInBabelJs] }, overrides)],
      }, options);
    },
    // ADD: Configurations which are customizable
    overrides: { presets: ['@babel/preset-env'] },
  },
  ...
};

[phated]

@sttk thank you! I like your idea but I want to think of the best way to implement it.

[phated]

@sttk I adjusted your idea slightly, but I like how this turned out! Now, a consumer can pass any config they want to override the default hook config, and it will completely replace all config except the { extensions } property.

Overriding the default config is a very advanced technique, so I'm only documenting it a tiny bit.

[phated]

I'm going to merge this, but will plan to cut the 3.0.0 release in the next couple of days. Please let me know if you see anything bad about this!