Work towards #56: Add permalink to every pattern

This makes cleaner URLs thanks to jekyll

prototype/index.md

@@ -2,6 +2,7 @@
 layout: pattern
 title: Prototype
 folder: prototype
+permalink: /patterns/prototype/
 categories: pattern_cat
 tags: pattern_tag
 ---
@@ -19,4 +20,4 @@ instance, and create new objects by copying this prototype.
 
 **Real world examples:**
 
-* [java.lang.Object#clone()](http://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#clone%28%29)
+* [java.lang.Object#clone()](http://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#clone%28%29)