The issue is a vague feature request for internationalization. Since the repository uses Express and Mongoose, research common i18n libraries for Node.js such as i18next. The contributor should first identify all user facing strings in the views and templates (likely in Jade/Pug or EJS). Then propose a locale file structure (e.g., en.json, es.json) and decide on a library. The issue lacks maintainer input, so clarification on scope and preferred library is needed.
Add i18n · madhums/node-express-mongoose-demo#147 | Good First Issue