Add option for a user-defined public API

[andrewrubin]

The idea here is to give developers a way to specify a set of YAML data within an /api directory, which, at build time, will compile to JSON in the /public directory.

Some things to consider (ideas, not requirements):

• recursive compilation of files within subfolders?
• establish a convention for merging index.yml files into every other data file in the same folder?

[ste-vg]

I think the static props helper it would be nice as well. Perhaps by default just returns some common predefined summary data. Something like

const summaryKeys = [
  'id',
  'date',
  'title',
  'image'
]

So for example lets say we have a folder api/movies/ and in the we have dude-wheres-my-car.yml, dragonheart.yml and manos-the-hands-of-fate.yml. Each YAML has id, title, image, year, description, openingWeekendEarnings.

If you requested {api: ['movies']} in the static props but without adding any extra settings it would return an array of those 3 movies with id, title, and image.

But if you provide your own settings it'll return that instead. Perhaps like...

 {api: [
    {
       id: 'movies, 
       limit: 2, 
       order: 'title', 
       keys: ['id', 'title', 'releaseDate', 'openingWeekendEarnings'] 
    }
]}

Or something like that

[andrewrubin]

Love that idea @ste-vg . I included that feature as a sub-feature to the other issue I filed this evening, but maybe it's better suited here.