* Make Undo & Redo and the menu buttons into actions; add undo/redo buttons
* Create variables for the ToolIcon colors
* Darken the menu buttons when they’re active
* Put the more intensive test in `perform`
* Fix & restyle hint viewer
* Add pinch zoom for macOS Safari
* Chrome/Firefox trackpad pinch zoom
* openedMenu → openMenu
* needsShapeEditor.ts → showSelectedShapeActions.ts
* Call showSelectedShapeActions
