Work towards #56: Splitting up the README

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

poison-pill/index.md

@@ -0,0 +1,20 @@
+---
+layout: pattern
+title: Poison Pill
+folder: poison-pill
+categories: pattern_cat
+tags: pattern_tag
+---
+
+**Intent:** Poison Pill is known predefined data item that allows to provide
+graceful shutdown for separate distributed consumption process.
+
+![alt text](./etc/poison-pill.png "Poison Pill")
+
+**Applicability:** Use the Poison Pill idiom when
+
+* need to send signal from one thread/process to another to terminate
+
+**Real world examples:**
+
+* [akka.actor.PoisonPill](http://doc.akka.io/docs/akka/2.1.4/java/untyped-actors.html)