docs: add diagrams for marker interface, master-worker, mediator, memento, metadata mapping, microservices api gateway, microservices log aggregation, monad, monitor, monostate, multiton, mute idiom

Author: iluwatar

marker-interface/README.md

@@ -37,6 +37,10 @@ Wikipedia says
 > 
 > To use this pattern, a class implements a marker interface (also called tagging interface) which is an empty interface, and methods that interact with instances of that class test for the existence of the interface. Whereas a typical interface specifies functionality (in the form of method declarations) that an implementing class must support, a marker interface need not do so. The mere presence of such an interface indicates specific behavior on the part of the implementing class. Hybrid interfaces, which both act as markers and specify required methods, are possible but may prove confusing if improperly used.
 
+Flowchart
+
+![Marker Interface flowchart](./etc/marker-interface-flowchart.png)
+
 ## Programmatic Example of Marker Interface Pattern in Java
 
 The Marker Interface design pattern is a design pattern in computer science that is used with languages that provide run-time type information about objects. It provides a means to associate metadata with a class where the language does not have explicit support for such metadata.

marker-interface/etc/marker-interface-flowchart.png

@@ -33,6 +33,10 @@ Wikipedia says
 
 > Master–slave is a model of asymmetric communication or control where one device or process (the master) controls one or more other devices or processes (the slaves) and serves as their communication hub. In some systems, a master is selected from a group of eligible devices, with the other devices acting in the role of slaves.
 
+Sequence diagram
+
+![Master-Worker sequence diagram](./etc/master-worker-sequence-diagram.png)
+
 ## Programmatic Example of Master-Worker Pattern in Java
 
 In the provided code, the `MasterWorker` class initiates the concurrent computation process. The `Master` class divides the work among `Worker` objects, each performing its task in parallel, thus optimizing task processing and enhancing system efficiency.

master-worker/README.md

@@ -33,6 +33,10 @@ Wikipedia says
 
 > In software engineering, the mediator pattern defines an object that encapsulates how a set of  objects interact. This pattern is considered to be a behavioral pattern due to the way it can  alter the program's running behavior. In object-oriented programming, programs often consist of  many classes. Business logic and computation are distributed among these classes. However, as  more classes are added to a program, especially during maintenance and/or refactoring, the  problem of communication between these classes may become more complex. This makes the program  harder to read and maintain. Furthermore, it can become difficult to change the program, since  any change may affect code in several other classes. With the mediator pattern, communication  between objects is encapsulated within a mediator object. Objects no longer communicate directly  with each other, but instead communicate through the mediator. This reduces the dependencies  between communicating objects, thereby reducing coupling.
 
+Sequence diagram
+
+![Mediator sequence diagram](./etc/mediator-sequence-diagram.png)
+
 ## Programmatic Example of Mediator Pattern in Java
 
 In this example, the mediator encapsulates how a set of objects interact. Instead of referring to each other directly, they use the mediator interface.
@@ -175,10 +179,6 @@ Here's the console output from running the example.
 14:05:15.083 [main] INFO com.iluwatar.mediator.PartyMemberBase -- Rogue arrives for dinner
 ```
 
-## Detailed Explanation of Mediator Pattern with Real-World Examples
-
-![Mediator](./etc/mediator_1.png "Mediator")
-
 ## When to Use the Mediator Pattern in Java
 
 Use the Mediator pattern when

master-worker/etc/master-worker-sequence-diagram.png

@@ -36,6 +36,10 @@ Wikipedia says
 
 > The memento pattern is a software design pattern that provides the ability to restore an object to its previous state (undo via rollback).
 
+Sequence diagram
+
+![Memento sequence diagram](./etc/memento-sequence-diagram.png)
+
 ## Programmatic Example of Memento Pattern in Java
 
 In our astrology application, we use the Memento pattern to capture and restore the state of star objects. Each state is saved as a memento, allowing us to revert to previous states as needed.

mediator/README.md

@@ -29,6 +29,10 @@ Wikipedia says
 
 > Create a "virtual [object database](https://en.wikipedia.org/wiki/Object_database)" that can be used from within the programming language.
 
+Flowchart
+
+![Metadata Mapping flowchart](./etc/metadata-mapping-flowchart.png)
+
 ## Programmatic Example of Metadata Mapping Pattern in Java
 
 Hibernate ORM Tool uses Metadata Mapping Pattern to specify the mapping between classes and tables either using XML or annotations in code.