Work towards #56: Splitting up the README

I did the job and splitted up the readme, hopefully everything was
splitted correctly...

front-controller/index.md

@@ -0,0 +1,23 @@
+---
+layout: pattern
+title: Front Controller
+folder: front-controller
+categories: pattern_cat
+tags: pattern_tag
+---
+
+**Intent:** Introduce a common handler for all requests for a web site. This
+way we can encapsulate common functionality such as security,
+internationalization, routing and logging in a single place.
+
+![alt text](./etc/front-controller.png "Front Controller")
+
+**Applicability:** Use the Front Controller pattern when
+
+* you want to encapsulate common request handling functionality in single place
+* you want to implements dynamic request handling i.e. change routing without modifying code
+* make web server configuration portable, you only need to register the handler web server specific way
+
+**Real world examples:** 
+
+* [Apache Struts](https://struts.apache.org/)