`Prev` & `Next` navigation links doesn't works if `trailingSlash` is set to `always`.

[gyurielf]

To be able to deploy to Amazon CDN(CF S3) we needed index.html files for every (prerendered) page. With @sveltejs/adapter-static trailingSlash, it can be done easily.

Basically it works as it should, the only broken thing what I found up to this point, that the Prev & Next buttons are broken.