Docs examples 08/14: Rework toggle, search, and sorting examples

Part 8 of 14 in the stack that splits up the approved draft !6295 (closed) into reviewable pieces. The content is exactly what was reviewed there; I've only sliced it.

Related to #3575.

Pages: toggle, search, sorting, segmented control. Realistic content and contextual placement. Toggle also gains two Behavior bullets documenting disabled and is-loading, since the page had no guidance to anchor those examples to.

Safe to publish without the MRs after it.