docs(wiki): add a user guide, and retire the roadmap
The wiki gains eleven pages covering how to use the app - getting started,
writing and formatting, tables, diagrams, files/folders/tabs, finding and
navigating, panels and layout, live updates and conflicts, pages/printing/
export, spell check, and the full keyboard shortcut list - linked from Home
and the sidebar.
Roadmap is deleted here as it is in the repository: the docs and tests are
the record of what shipped. FlowchartCanvas is replaced by DiagramCanvas,
which is what the control is now called, and the three control docs that had
never been mirrored (ChangeHighlightAdorner, DiagramCanvas, VideoPlayerView)
are added so the reference matches docs/controls/.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
docs: sync control pages for Page View and Panel Chrome (PanelHeader, PanelColumn, DocumentSheetBackdrop, PrintPreviewPages)
Add PageView control doc; note Page View in MarkdownRichEditor
Mirrors the feature/page-view control docs (INV-058).