will there be version 3 docs made for when version 3 stable is released

Of course, it's all there in the 3.x branch, there's a brand new docs build system and a new blog section. You can already see most of the 3.x docs content you need on https://twill.io/docs/3.x too.

Idk about other pages but this one looks the same even though it’s the 3.x URL

that's fixed on the new docs system