Finds the best matching language from Accept-Language header.
$ npm install --save detect-language
var app = require('express');
var locale = {
supportedLanguages: ['de', 'fr', 'pl', 'en-GB', 'en-US'],
defaultLanguage: 'en'
};
app.use(require('./src/i18n/detect-language')(locale));
// req.lang is set to detected language
MIT © Damian Krzeminski