* Add theme colors from Figma
* Rough-in of AppHeader
* Add styled ActionButton
* Add react-router and placeholder Settings page
* Add ability to set persistent defaultDir
* Add react-hot-toast for save success message
* Add defaultProjectName setting
* Handle case of stale empty defaultDir in storage
* Wrap app in BrowserRouter
* Wrap test App in BrowserRouter
* Don't need BrowserRouter outside of testing
because we use RouterProvider
