concurrent worklow example

Author: nassor

CONCURRENT_WORKFLOW.md

@@ -38,6 +38,10 @@ path = "examples/workflow_simple.rs"
 name = "workflow_book_prepositions"
 path = "examples/workflow_book_prepositions.rs"
 
+[[example]]
+name = "workflow_concurrent_book_prepositions"
+path = "examples/workflow_concurrent_book_prepositions.rs"
+
 [[example]]
 name = "workflow_negotiation"
 path = "examples/workflow_negotiation.rs"