需求：本着提高用户体验，自动跳转到用户选择的语言

一开始对next文档没看全，计划用中间件处理每个请求，
当用户切换语言，写到cookie，然后用next middleware来根据cookie携带的locale，redirect到对应locale

后来看到next有默认cookie来处理这方面优先级

下面是根据文档的实践

Automatic Locale Detection

When a user visits the application root (generally /), Next.js will try to automatically detect which locale the user prefers based on the Accept-Language header and the current domain.

开启auto detection

浏览器语言优先级—初始en最高

切换浏览器语言优先级—zh最高

当访问默认地址，会307重定向到accept-language携带的最优先级的语言

利用设置特定cookie实现覆盖自动探测

Leveraging the NEXT_LOCALE cookie

Next.js supports overriding the accept-language header with a NEXT_LOCALE=the-locale cookie. This cookie can be set using a language switcher and then when a user comes back to the site it will leverage the locale specified in the cookie when redirecting from / to the correct locale location.