Work towards #56: Add permalink to every pattern

This makes cleaner URLs thanks to jekyll

model-view-presenter/index.md

@@ -2,6 +2,7 @@
 layout: pattern
 title: Model-View-Presenter
 folder: model-view-presenter
+permalink: /patterns/model-view-presenter/
 categories: pattern_cat
 tags: pattern_tag
 ---
@@ -14,4 +15,4 @@ developers to build and test user interfaces.
 **Applicability:** Use the Model-View-Presenter in any of the following
 situations
 * when you want to improve the "Separation of Concerns" principle in presentation logic
-* when a user interface development and testing is necessary.
+* when a user interface development and testing is necessary.