Document Ctrl-held widget stack list
Document type-based widget IDs for new widgets (PR #3022)
Edit Mode: document the shared selection bar and the widget stack under the cursor The widget switcher of the JSON editor is now a selection bar that Edit Widgets carries too, the F-key panel is a clickable stack list, and Alt+click drills down through the widgets at a point (PR #3123).
Remove info relocated elsewhere
Split Edit Mode page into eight Editing JSON subsections Break the Edit Mode page out into one page per Menu button (Edit Widgets, History, JSON, Widgets, Debug, Assets, Toolbox, Game Settings) under the Editing JSON section of the sidebar. Content is moved unchanged; the JSON page also keeps the editor-wide material (overview, top toolbar, menu, selecting widgets, widget toolbar). Editing JSON gains an overview of the new subsections, and inbound links were updated.