Localization: Croatian and Serbian

[m-gallesio]

Prerequisites

• I have searched for duplicate or closed feature requests.
• I have read the contributing guidelines.

Greetings.
We use this library in our project, and we are going to need localizations for Croatian and Serbian.
We do not know yet if our customer will use Cyrillic or Latin for Serbian, but of course a general purpose library would appreciate both.

Of course I realize this would be unpaid development, but this being a project open to contributions I am leaving this open in case any speaker is interested in providing them so they may be guaranteed to be correct.

If no-one is available we will likely contribute this ourselves via some dictionary / automated tool since we need this by the end of the year.
Regards.

[Eonasdan]

I can't be responsible for creating new locales, specially ones I don't speak. You can look at existing locales and create a PR based on that. Momentjs/day.js and my picker share similarities on what the locales are like. It's possible that one of those other libraries have the basics for those locales you can start from.