Work towards #56: Splitting up the README

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

builder/index.md

@@ -0,0 +1,23 @@
+---
+layout: pattern
+title: Builder
+folder: builder
+categories: creational
+tags: pattern_tag
+---
+
+**Intent:** Separate the construction of a complex object from its
+representation so that the same construction process can create different
+representations.
+
+![alt text](./etc/builder_1.png "Builder")
+
+**Applicability:** Use the Builder pattern when
+
+* the algorithm for creating a complex object should be independent of the parts that make up the object and how they're assembled
+* the construction process must allow different representations for the object that's constructed
+
+**Real world examples:**
+
+* [java.lang.StringBuilder](http://docs.oracle.com/javase/8/docs/api/java/lang/StringBuilder.html)
+* [Apache Camel builders](https://github.com/apache/camel/tree/0e195428ee04531be27a0b659005e3aa8d159d23/camel-core/src/main/java/org/apache/camel/builder)