Surprisingly there is not a proper plugin for this. I found a couple gists that do this:
I didn’t see anything in the npm repo, so...
Install:
npm i --save mongoose mongoose-i18n
Create your schema:
mongoose = require 'mongoose'
i18nPlugin = require 'mongoose-i18n'
# ... create your schema, e.g. MySchema ... #
MySchema.plugin i18nPlugin, languages: ['en', 'fr'], defaultLanguage: 'en'