add i18n support

[neatstudio]

• add flatpickrLocales to flatpickr.js and build it
• usage:

Flatpickr::make('created_at')->label('Created At')
    ->customConfig([
        'locale' => 'zh', //'zh_tw' ,'ru', or others [only can be string]
    ])->monthSelect(),

[what-the-diff]

PR Summary

• Brought in foreign language support for the calendar tool! 🌐
  We've essentially borrowed something called flatpickrLocales from the 'flatpickr/dist/l10n' library. This is like calling upon an online translator to help us out!

• Connected the language support to our datepicker! 📅 🔀
  We integrated the localization feature into our datepicker function, flatpickrDatepicker. It's like teaching our calendar to speak different languages - now it can talk to you in style, in any language you choose! Super cool, right? 🕺💃

[neatstudio]

fix #39