Publish plotly.js-locales to npm

[etpinard]

resolves #3083, a continuation from #2670 (the partial-bundle-pkgs PR)

As locale files are fairly small, I decided to publish only one plotly.js-locales package (as opposed to one per locale) and ask users (in the plotly.js-locales README) to grab to relevant locale as:

// ES6 module
import Plotly from 'plotly.js';
import locale from 'plotly.js-locales/fr';

// CommonJS
var Plotly = require('plotly.js');
var locale = require('plotly.js-locales/fr');

// then
Plotly.register(locale);

that is, users would npm-download all the locales, but only bundle the locale(s) they need.

Reviewers can look at:

publish-locales...publish-locales-build

to see to generated git-ignored files in build/.

cc @plotly/plotly_js and @nicolaskruchten who may find this useful for RCE and dash users.

[alexcjohnson]

Good call 👍

[alexcjohnson]

@etpinard this looks great! Assuming you've verified that the built files work as described in the README (and they certainly look like they will) 💃

[etpinard]

Assuming you've verified that the built files work as described

Verified ✅