docs(custom-plugins): add overview image (datahub-project#11634)

metadata-models-custom/README.md

@@ -204,6 +204,19 @@ that were loaded for debugging purposes.
 }
 ```
 
+#### Custom Plugin Ecosystem Overview
+
+The following diagram shows the overall picture of the various validators, mutators, and side effects shown within
+the context of typical read/write operations within DataHub. Each component is discussed in further detail in the 
+sections below.
+
+<p align="center">
+  <img width="80%"  src="https://raw.githubusercontent.com/datahub-project/static-assets/main/imgs/metadata-models-custom/custom-plugin-overview.svg"/>
+</p>
+
+In the diagram above, the circles represent Aspects (custom aspects or standard). As the Aspects progress they can be mutated/changed,
+rejected, or additional aspects can be generated by side effects.
+
 #### Custom Validators
 
 Custom aspects might require that instances of those aspects adhere to specific conditions or rules. These conditions could vary wildly depending on the use case however they could be as simple