Don't mention async sequences in the GRDBAsyncDemo introduction

Been there, done that: when one feeds a SwiftUI view from an async sequence, the view MUST display an initial empty state, until the Swift Concurrency runtime provides the initial value of the sequence. That's why the demo app uses a Combine publisher for feeding views with database value. This commit removes a misleading reference to async sequences.

Fix #1532

Documentation/DemoApps/GRDBAsyncDemo/README.md

@@ -13,8 +13,9 @@ The topics covered in this demo are:
 
 - How to setup a database in an iOS app.
 - How to define a simple [Codable Record](../../../README.md#codable-records).
-- How to track database changes and animate a SwiftUI List with an async sequence built from [ValueObservation](https://swiftpackageindex.com/groue/grdb.swift/documentation/grdb/valueobservation).
+- How to track database changes and animate a SwiftUI List with [ValueObservation](https://swiftpackageindex.com/groue/grdb.swift/documentation/grdb/valueobservation) Combine publishers.
 - How to apply the recommendations of [Recommended Practices for Designing Record Types](https://swiftpackageindex.com/groue/grdb.swift/documentation/grdb/recordrecommendedpractices).
+- How to perform `async` database accesses.
 - How to feed SwiftUI previews with a transient database.
 
 **Files of interest:**