The reason I'm adding it is that recently I almost submitted
a patch in which I wrote a language code with the Cyrillic letter о
instead of the corresponding Latin letter. It's not a perfect test,
but it's good enough for a basic check.
Additional changes in this PR include,
* Added composer.json
* Refactored the folder structure.
* Added editorconfig.
* Added PHPCS and formatted existing code.
* Changes to use a single license - GPL-2.0-or-later
* ESLint related fixes
Bug: T218639