[fix] docs

Author: yawnt

Diff for: README.md

@@ -5,6 +5,42 @@ Caronte is an HTTP programmable proxying library that supports
 websockets. It is suitable for implementing components such as
 proxies and load balancers.
 
+### Core Concept
+
+A new proxy is created by calling `createProxyServer` and passing
+an `options` object as argument ([valid properties are available here](https://github.com/yawnt/caronte/blob/master/lib/caronte.js#L26-L39)) 
+
+```javascript
+var caronte = require('caronte');
+
+var proxy = caronte.createProxyServer(options);
+```
+
+An object will be returned with four values:
+
+* web `req, res, [options]` (used for proxying regular HTTP(S) requests)
+* ws `req, socket, head, [options]` (used for proxying WS(S) requests)
+* ee (an EventEmitter2 that emits events, you can hook into them to customize behaviour)
+* listen `port` (a function that wraps the object in a webserver, for your convenience)
+
+Is it then possible to proxy requests by calling these functions
+
+```javascript
+require('http').createServer(function(req, res) {
+  proxy.web(req, res, { target: 'http://mytarget.com:8080' });
+});
+```
+
+When a request is proxied it follows two different pipelines ([available here](https://github.com/yawnt/caronte/tree/master/lib/caronte/passes))
+which apply trasformations to both the `req` and `res` object. 
+The first pipeline (ingoing) is responsible for the creation and manipulation of the stream that connects your client to the target.
+The second pipeline (outgoing) is responsible for the creation and manipulation of the stream that, from your target, returns datas 
+to the client.
+
+You can easily add a `pass` (stages) into both the pipelines (XXX: ADD API).
+
+In addition, every stage emits a corresponding event so introspection during the process is always available.
+
 ### Contributing and Issues
 
 * Search on Google/Github