Work on #213

- properly categorize all patterns
- remove pattern list from readme
- minor fixes to readme
- removed "introduction" because its not a pattern and an error i
committed some time ago

mediator/index.md

@@ -3,8 +3,8 @@ layout: pattern
 title: Mediator
 folder: mediator
 permalink: /patterns/mediator/
-categories: behavioral
-tags: pattern_tag
+categories: Behavioral
+tags: Java
 ---
 
 **Intent:** Define an object that encapsulates how a set of objects interact.