国际化
https://www.w3.org/International/questions/qa-choosing-language-tags
语言及子标签注册表
https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
语言及子标签查找、 检查子标签是否正确
https://r12a.github.io/app-subtags/
中文简繁转换
https://github.com/BYVoid/OpenCC
CSS 实现简繁转换
css
font-variant-east-asian: traditional;作用是将页面上所有的简体都转成繁体，需要字体支持或者在OS X和iOS有效，改变的仅是展示的字形，实际在
dom中还是为简体
https://www.zhangxinxu.com/wordpress/2021/01/css-simplified-traditional-chinese/comment-page-1/