Documentation for migrating from navigation-next to Atlassian Navigation

I’m trying to migrate an app from navigation-next to page-layout and side-navigation, but the relevant documentation appears to be missing. It should be located at this url, according to the readme for the old component, but it seems it got lost after the move from atlaskit.atlassian to

Does anyone know of another copy of the documentation or have any pointers to help in the migration? I tried looking for cached versions on Google and the Wayback Machine, but they both came up empty.