Adaptations page has confusing leftnav position

[mit-mit]

The page https://docs.flutter.dev/platform-integration/platform-adaptations discusses the automatic UI adaptions performed by the Flutter framework. However for some reason it is placed in the leftnav under the "Beyond UI" section in the "Platform integration" subsection. That seems confusing as all the adaptations are UI related. I suggest it should be moved to the "User Interface" section in the "Adaptive and responsive" design subsection.

[mit-mit]

cc @jmagman @goderbauer

[LukeDevNation]

Totally agree, it makes more sense for the page to be under (user interface > adaptive and responsive) since it’s all about UI adaptations. Placing it under 'Beyond UI' could confuse those looking for specific information on adaptive interfaces. It would be great to move it to make it easier to find.

[jmagman]

I think it makes sense. cc @parlough who moved it there last year #9182