docs: add diagrams for spatial partition, special case, specification, state, step builder, strangler, strategy, subclass sandbox

state/README.md

@@ -38,6 +38,10 @@ Wikipedia says
 
 > The state pattern is a behavioral software design pattern that allows an object to alter its behavior when its internal state changes. This pattern is close to the concept of finite-state machines. The state pattern can be interpreted as a strategy pattern, which is able to switch a strategy through invocations of methods defined in the pattern's interface.
 
+Flowchart
+
+![State flowchart](./etc/state-flowchart.png)
+
 ## Programmatic Example of State Pattern in Java
 
 In our programmatic example there is a mammoth with alternating moods.