Summary
You just have got a basic lightweight multi-language functionality that you can use in your web application.
Note, however, that translation layer may require many code enhancements and performance optimizations, for you to be ready to use it for production purposes.
Source Code
You can find the source code as an Angular CLI project in the angular/i18n folder.
You can also check out one of my Angular projects @ngstack/translate that provides i18n-features for Angular applications and components. That library can save a lot of your time and effort required to build a multi-lingual web application.