Converting between iso-639-3 to iso-639-1 language codes.
For languages without iso-639-1 that have a "macro language", It will return the "macro language" iso-639-1 code (if exists)
npm:
npm install --save iso-639-3-to-1
const convert3To1 = require('iso-639-3-to-1')
let iso639code = 'cmn';
let result = convert3To1(iso639code);
// result = 'zh'