Description

Currently, if you navigate to a previous version of a page using a version-specific URL like: https://v13.angular.io/guide/architecture, there is a banner at the top saying that:

This is the archived documentation for Angular v13.
Please visit [angular.io](https://angular.io/) to see documentation for the current version of Angular.

The link brings you to the homepage for the current version. This is quite inconvenient as you need to find the same page again (or go back, copy'n'paste the path from the URL and construct the URL yourself).

There are 2 improvements that we can make:

• in vast majority of cases, the same page would be available on angular.io. In this case, we can construct a full URL that would lead to the most up-to-date version. In my example, instead of redirecting to just https://angular.io, we can have a link in the banner to go to https://angular.io/guide/architecture instead (same URL without v13)
• since in some cases the page would be missing, we can improve the "page not found" UI as well: the URL may contain a special GET param: https://angular.io/guide/architecture?redirected_from=v13 and we can render an extra note on the "page not found" page to say something like: "You were redirected from v13 docs, but this page doesn't exist in the new version. Please use the search box above or browse the list of topics to find the necessary page.".