Add the core concepts image for the how novu works page (#902)

Author: Aviatorscode2

content/docs/platform/how-novu-works.mdx

@@ -22,6 +22,8 @@ When a workflow includes an in-app step, messages are routed to the subscriber
 
 At a high level, Novu’s architecture is built around modular but connected concepts. Each concept serves a specific role in the delivery pipeline and is scoped to an environment.
 
+![How Novu works](/images/how-novu-works.png)
+
 ### Organization and environments
 
 Everything starts with your organization, the top-level entity in Novu. Each organization can have multiple environments, such as: