First Class i18n Support - Multiple Language Support for a Single Form

So it would be great for single forms to be able to have multiple translation variations.

Probably the cleanest way would be using i18n strings.

Ideally we'd be able to specify the language tags ourselves, as it can be different per implementation e.g. en-US, en-UK, pt-PT, pt-BR etc. which is the ISO standard afaik. But some prefer to use e.g. just 'en' for US english, 'br' for Brazilian Portuguese. 

You could potentially make use of this:

https://github.com/txty-io/texterify

It has transitioned from a BSL to Apache v2 license. I've used their managed solution for years and it's been great.

There is also inlang/opral:

https://github.com/opral/monorepo/tree/main/inlang

I only use paraglide from inlang/opral and it's quite nice for the front end, but not sure about their string management solution as I have not tried that.

We'd need to be able to send the language tag to the form, particularly for embedded ones, to ensure it's possible to make sure the correct language can be loaded matching the currently used language on the site it is embedded on.

Could perhaps have a json file that is downloadable for the primary language as well as uploading the translated versions. Could also potentially allow editing the strings inside the web panel and machine translations also.

E.g. opnform.com/forms/uuid/en-US could use the en-US.json file, opnform.com/forms/uuid/pt-BR could use the pt-BR.json file etc.

This would also allow using languages that aren't officially supported yet also, so we could provide our own translations for all form fields, success/error messages etc.

Alternatively, it could be limited to languages officially supported. In that case, the translations would only need to cover the user modified parts. Just ideally would still use a url structure like above so it follows standards and all user cases could be covered.