Work towards #56: Splitting up the README

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

service-locator/index.md

@@ -0,0 +1,27 @@
+---
+layout: pattern
+title: Service Locator
+folder: service-locator
+categories: pattern_cat
+tags: pattern_tag
+---
+
+**Intent:** Encapsulate the processes involved in obtaining a service with a
+strong abstraction layer.
+
+![alt text](./etc/service-locator.png "Proxy")
+
+**Applicability:** The service locator pattern is applicable whenever we want
+to locate/fetch various services using JNDI which, typically, is a redundant
+and expensive lookup. The service Locator pattern addresses this expensive
+lookup by making use of caching techniques ie. for the very first time a
+particular service is requested, the service Locator looks up in JNDI, fetched
+the relevant service and then finally caches this service object. Now, further
+lookups of the same service via Service Locator is done in its cache which
+improves the performance of application to great extent.
+
+**Typical Use Case:**
+
+* when network hits are expensive and time consuming
+* lookups of services are done quite frequently
+* large number of services are being used