Add a short overview, example, and credits to README.

README.md

@@ -0,0 +1,35 @@
+### What is it?
+
+**FabricJS** is a framework that makes it easy to work with HTML5 canvas element. It is an **interactive object model** on top of canvas element. It is also an **SVG-to-canvas parser**.
+
+### What are the features?
+
+- Unit tested
+- Modular
+- Cross-browser
+- Fast
+
+### How do I use it?
+
+#### Adding red rectangle to canvas
+  
+    <canvas id="canvas" width="300" height="300"></canvas>  
+    ...
+    
+    var canvas = new Canvas.Element('canvas');
+    
+    var rect = new Canvas.Rect({
+      top: 100,
+      left: 100,
+      width: 60,
+      height: 70,
+      fill: 'red'
+    });
+    
+    canvas.add(rect);
+
+### Credits
+
+- Ernest Delgado, for the original idea of [manipulating images on canvas](http://www.ernestdelgado.com/archive/canvas/).
+- [Maxim "hakunin" Chernyak](http://twitter.com/hakunin), for ideas, and help with various parts of the library.
+- Sergey Nisnevich, for help with object and group manipulation logic.