Updating the README.

Author: lemire

README.md

@@ -2,8 +2,12 @@
 [![Build Status](https://travis-ci.org/lemire/FastIntegerCompression.js.png)](https://travis-ci.org/lemire/FastIntegerCompression.js)
 
 This is an integer compression library in JavaScript, useful for work on indexes.
-Given an array of integers, it produces an ArrayBuffer that uses far fewer bytes
-than the original. You can later recover the original array quickly.
+Given an array of small integers, it produces an ArrayBuffer that uses far fewer bytes
+than the original (using VByte compression). It assumes a modern JavaScript engine with
+typed arrays.
+ 
+From the compressed data, you can later recover the original  array quickly 
+(at a rate of millions of integers per second).
 
 
 ```javascript
@@ -22,17 +26,26 @@ This code is made available under the Apache License 2.0.
 
 ## Performance numbers
 
+This library is meant to compress arrays of small integers. It is not meant to
+compress text documents or arrays of large (or random) integers.
+
+## Performance numbers
+
 Go to benchmark repository (check the README.md file) and run the benchmark:
 
 ```bash
-$ nodejs test.js
+$ node test.js
 Platform: linux 3.13.0-91-generic x64
 Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
 Node version 4.5.0, v8 version 4.5.103.37
 
 input size: 7.813K compressed size: 1000B
-FastIntegerCompression.compress x 347,635 ops/sec ±1.06% (93 runs sampled)
+FastIntegerCompression.compress x 337,845 ops/sec ±0.93% (92 runs sampled)
 Fastest is FastIntegerCompression.compress
-FastIntegerCompression.uncompress x 162,411 ops/sec ±0.58% (92 runs sampled)
+FastIntegerCompression.uncompress x 187,694 ops/sec ±0.72% (93 runs sampled)
 Fastest is FastIntegerCompression.uncompress
 ```
+
+These numbers means that we can uncompress 187,694 1000-integer arrays per second.
+That's 187 millions of integers per second.
+