I've tried adding locales to my docs by moving my primary docs into a /en directory, and duplicating it to /zh for chinese translations. I've also added a redirect to default to /en by adding redirect: /en to a docs/index.md page.

All this works, and I can access the translated docs by changing /en to /zh in the url, however when I try changing language from the dropdown in the menu, it redirects to /en/zh.

This can be seen here:
https://docs.page/tqwewe/kameo~book-zh

1. Visit the url linked above
2. You'll automatically be redirected to /en
3. Change language to Chinese in the dropdown
4. See 404 page, as the url is /en/zh

You can see the links are wrong in the source html too.