Updated readme

More information on how to use this module

Readme.md

@@ -3,24 +3,68 @@
 # Stureby Index
 This is an simple index or cache for javascript.
 
+Install the module simply with npm or yarn
+
+```
+npm i --save stureby_index
+```
+
+or
+
+```
+yarn add stureby_index
+```
+
 Create the index instance by simply requiring the stureby_index module and create a
 new instance of the object.
 
+```
+var shIndex = require('stureby_index');
+const idx = shIndex(idxPath);
+```
+
 Then you can use the put, get and search methods to modify the index.
 
+```
+idx.put('as', 'the beste1');
+idx.put('asa', 'the beste2');
+idx.put('asas', 'the beste3');
+idx.put('asasas', 'the beste4');
+console.log(idx.get('asasas')) // 'the beste4'
+```
+
 The first argument to the put method is the key and the second is the value.
 The same key can be linked to multiple values.
 
 The search method will return a list of matched keys.
 
+```
+console.log(idx.search('asas')); // ['asas', 'asasas']
+```
+
 ## Version 2
 The new version is backwards compatible with version 1 of the index. The index
 will be upgraded and once it is flushed back to disk the process is not reversible.
 
+This version adds the following methods:
+
+- toJSON()
+- delete(key)
+- clear()
+
 ### Don't persist on disk
 In this version it is possible to create a index without the disk access. The
 options parameter should include persist false which will use the noop_storage.
 
+## Version 3
+
+This version has an internal cache for the open indexes so if you try to access the same path from different parts 
+of the code in the same javascript vm you will write and read from a single instance.
+
+This version adds the following methods:
+
+- size()
+
 ## Flush before process exists
 ```
   if(!_.isUndefined(process)) {