Checklist of steps for deploying a new language variant to production:
- Languages mni-Beng and mni-Mtei defined
- LanguageConverter support (T357853)
- Translatewiki support for new language codes
- Front end redirect rules so that https://mni.wikipedia.org/mni-Beng/.... works
- Wikidata/wikibase support for new language codes
- CLDR support (T313883)
Anything else I'm missing?