The architecture of scala collections should have a link to the 2.13 sister page

[MasseGuillaume]

This page: https://docs.scala-lang.org/overviews/core/architecture-of-scala-collections.html
Should link to that page: https://docs.scala-lang.org/overviews/core/architecture-of-scala-213-collections.html#inner-main

Something like a warning on the top of the old documentation that you should be looking at the 2.13.x page.

[SethTisue]

PR: #1456