Backport changes to reference docs from 3.2.0

[bishabosha]

did a rebase of release-3.2.0 onto language-reference-stable and fixed conflicts

fixes #16201

[bishabosha]

I think I need to change nightlyOf to movedTo in the front matter

[bishabosha]

now I added only changes to the reference docs, the sidebar and the layout

[bishabosha]

How I fixed it: Take the latest language-reference-stable branch, e.g. commit 5b81f19. Rebase release-3.2.0 onto it, fixing any conflicts. Then adjust all nightlyOf occurrences in the markdown front matter to movedTo. Then unstage all commits by resetting to the reference stable head with git reset 5b81f19, then add only the reference docs changes with git add docs/_docs/reference and git add project/resources/referenceReplacements

[bishabosha]

I suggest this also to be added as a step in the release procedure

[julienrf]

I wonder if a merge would work better than a rebase?

[bishabosha]

I wonder if a merge would work better than a rebase?

I guess in case changes occur independently? in this case it seems the changes don't overwrite anything