Updated readme

Author: mjohnson12

Samples/AsyncWorker/README.md

@@ -5,3 +5,5 @@ Demonstrates how to create a `WorkflowConcurrency` async `Worker`.
 This is an example of how you would create a closure based network request from within the async function of a `WorkflowConcurrency` `Worker`.
 
 `AsyncWorkerWorkflow.swift` contains the `Worker` implementation.
+
+This sample uses a local swift package reference for Workflow so that the Development.podspec didn't have to have it's iOS deployment target increased to iOS 13+.