Add Belarusian localization.

[spoooyders]

This is not 100% accurate since there is no single technical dictionary for belarusian language.
(And language itself is in a dire state because of 26 years long russian occupation of Belarus with strong anti-belarusian cultural and language policy).

I tried to use the following dictionaries:

• https://github.com/quendimax/kamputerm/blob/master/src/kamputerm.xml (IT-oriented dictionary project from 2010s)
• https://verbum.by

and common sense. This should be good enough as a first step. Later after I try it in practice - probably will adjust some parts.

[spoooyders]

I also have a question: do you accept only translations named after ICU locales?

Asking because Belarusian language really have at least 3 variants:

• be-BY - Беларуская - cyrillic version, "narkamauka" lexic, "official" variant in ICU - enforced by USSR government and not considered as real belarusian by many belarusians) - this is the variant I used in this particular PR.
• be-LAT - Беларуская (Лацінка) - latin variant with Tarashkevicz lexic, pre-USSR, missing from ICU, but accepted by many belarusian people as one of the true belarusian variants, keyboard layout for it is even present in Linux out-of-box as by(latin).
• be-TARASK- Беларуская (Тарашкевіца) - cyrillic variant with Tarashkevicz lexic, pre-USSR, missing from ICU, but accepted by many belarusians as one of the true belarusian variants.

If you accept such variations - I can do all 3 of them. I am especially interested in be-LAT variant since I am using it a lot.

[the-djmaze]

Languages are based on the browser Accept-Language header.
https://www.rfc-editor.org/rfc/rfc9110#field.accept-language

You probably already read https://github.com/the-djmaze/snappymail/blob/master/snappymail/v/0.0.0/app/localization/README

So you can have:

• be as the default Belarusian language
• be-BY for Belarusian in Belarus
• be-PL for Belarusian in Poland

I have no idea how browsers "accept" the Latin versions. Is it be-LAT or be-BY-LAT or be-BY-latin or something else?

[the-djmaze]

You can also check https://snappymail.eu/translate.php?lang=be

[spoooyders]

@the-djmaze Ok, thanks a lot for the detailed answers and links, I will figure out all that.