Added cqrs overview

README.md

@@ -1,6 +1,12 @@
 # ddd-cqrs-4-java-example
 Example applications and microservices that use [ddd-4-java](https://github.com/fuinorg/ddd-4-java) and [cqrs-4-java](https://github.com/fuinorg/cqrs-4-java) libraries and an [EventStore](https://eventstore.org/) to store the events (Event Sourcing).
 
+## Background
+This application shows how to implement DDD/CQRS without a framework, just with a few small libraries. 
+
+Here is a short architectural overview of how a CQRS/Event Sourced application looks like: 
+[![Overview](https://raw.github.com/fuinorg/ddd-cqrs-4-java-example/master/doc/cqrs-overview-small.png)](doc/cqrs-overview.png)
+
 ## Components
 - **[Shared](shared)** - Common code for all demo applications (commands, events, value objects and utilities).
 - **[Aggregates](aggregates)** - DDD related code for all demo applications (aggregates, entities and business exceptions).