Integrate mdn-data npm package

[teoli2003]

We are currently using data stored in the mdn-data by directly accessing the github file from kumascript.

We agreed this was a bad idea, and a temporary workaround.

As I am moving the data stored in {{InterfaceData}} macro (macros/InterfaceData.json) in mdn/data [I don't want to extend the workaround solution, now that we have TheGoodWay(tm) of doing it], I need kumascript to be able to access mdn/data content like it does for mdn/browser-compat-data.

Once this is done, I will be able to create a new macro using it, and we will be able to remove direct calls to github from 4 macros :-)

I'm not 100% sure I've not done all the set-up needed here. So be especially careful during the review. Thank you very much.

[escattone]

This looks great, thanks @teoli2003!

The mdn-browser-compat-data npm package has a basic test in test-api.js called 'A template can import an npm module with require()'. You could look at that test and add mdn-data to it, or maybe we should make that test only about mdn-browser-compat-data and add a new one for mdn-data? Or, if you prefer, I can re-factor the tests to include both.

[Elchi3]

Or, if you prefer, I can re-factor the tests to include both.

@escattone do you have time to do this?

[escattone]

@Elchi3 Although I'm consumed with the CDN work at the moment, I'll find a way to squeeze this into my work flow over the next few weeks (if that's not too late?).

[wbamberg]

Superseded by #1126.