Add recipe for Standard (non-modal) bottom sheet strategy #69
Description
It looks like the work on the Modal bottom sheet strategy is in progress, which brings me to a question about Standard bottom sheets using BottomSheetScaffold. The possible implementation seems close to a two-pane layout, since you always have the main content visible alongside the sheet.
The interesting twist is that the bottom sheet content can be in various states (collapsed, expanded), and we should be able to represent this state somehow (in the navigation key?). This would allow us to, for example, deep link directly to the expanded bottom sheet. Back-handling should also collapse the bottom sheet if it's expanded. This feels like a great opportunity to show off Nav3's flexibility.
A typical use case for this is a Spotify-like music player, where the bottom sheet represents the "currently playing" song. In apps like this, you typically need to provide some deep link to a currently playing song, which would mean a deeplink to an expanded bottom sheet.