#354 Add maven model for feature toggle design pattern

singleton/index.md

@@ -10,26 +10,28 @@ tags:
  - Difficulty-Beginner
 ---
 
-**Intent:** Ensure a class only has one instance, and provide a global point of
+## Intent
+Ensure a class only has one instance, and provide a global point of
 access to it.
 
 ![alt text](./etc/singleton_1.png "Singleton")
 
-**Applicability:** Use the Singleton pattern when
+## Applicability
+Use the Singleton pattern when
 
 * there must be exactly one instance of a class, and it must be accessible to clients from a well-known access point
 * when the sole instance should be extensible by subclassing, and clients should be able to use an extended instance without modifying their code
 
-**Typical Use Case:**
+## Typical Use Case
 
 * the logging class
 * managing a connection to a database
 * file manager
 
-**Real world examples:**
+## Real world examples
 
 * [java.lang.Runtime#getRuntime()](http://docs.oracle.com/javase/8/docs/api/java/lang/Runtime.html#getRuntime%28%29)
 
-**Credits**
+## Credits
 
 * [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)