Add pt-br.json (#2753)
* Add pt-br.json
* Fix json name, changelog
* Format file
* Fix json name
* Fix CHANGELOG.md
* Rename pt-br.json to pt-BR.json
* Update CHANGELOG.md
* Update CHANGELOG.md
* Update i18n.test.ts
Co-authored-by: freddyaboulton <alfonsoboulton@gmail.com>
Co-authored-by: Abubakar Abid <abubakar@huggingface.co>
