Support non-JP branches / EN, KR などのサポート

[neet]

Since refined-itsukara-link is just a front-end service that proxies JSON responses from Nijisanji's official scheduler itsukara.link, we cannot show Niji-EN and other branches' live schedules as long as Nijisanji does not provide schedules at the official website.

Itsukara.link does not seem to be maintained frequently, and since they haven't released any updates over a year, I think it is unlikely to support overseas branches on their own website.

To achieve this, we have to make our own database that also indexes overseas branches instead of mirror data from itsukara.link.

I'm recently working on this on my days off. You can see the latest in-progress source code at api directory on this repository.

[neet]

Updates are on the Gh Projects https://github.com/users/neet/projects/2