https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags

null-object/README.md

@@ -5,8 +5,7 @@ folder: null-object
 permalink: /patterns/null-object/
 categories: Behavioral
 tags:
- - Java
- - Difficulty-Beginner
+ - Extensibility
 ---
 
 ## Intent
@@ -25,7 +24,8 @@ Object is very predictable and has no side effects: it does nothing.
 ## Applicability
 Use the Null Object pattern when
 
-* you want to avoid explicit null checks and keep the algorithm elegant and easy to read.
+* You want to avoid explicit null checks and keep the algorithm elegant and easy to read.
 
 ## Credits
+
 * [Pattern Languages of Program Design](http://www.amazon.com/Pattern-Languages-Program-Design-Coplien/dp/0201607344/ref=sr_1_1)