docs(README.md): add note for legacy branch

README.md

@@ -1,6 +1,8 @@
 ![Showdown](https://raw.githubusercontent.com/showdownjs/logo/master/dist/logo.readme.png)
 
-[![Build Status](https://travis-ci.org/showdownjs/showdown.svg?branch=master)](https://travis-ci.org/showdownjs/showdown)
+[![Build Status](https://travis-ci.org/showdownjs/showdown.svg?branch=master)](https://travis-ci.org/showdownjs/showdown) [![npm version](https://badge.fury.io/js/showdown.svg)](http://badge.fury.io/js/showdown) [![Bower version](https://badge.fury.io/bo/showdown.svg)](http://badge.fury.io/bo/showdown)
+
+------
 
 Showdown is a Javascript Markdown to HTML converter, based on the original works by John Gruber. Showdown can be used client side (in the browser) or server side (with NodeJs).
 
@@ -39,6 +41,11 @@ In theory, Showdown will work in any browser that supports ECMA 262 3rd Edition
 Showdown has been tested with node 0.8 and 0.10. However, it should work with previous versions, such as node 0.6.
 
 
+## Legacy version
+
+If you're looking for showdown v<1.0.0, you can find it in the [**legacy branch**](https://github.com/showdownjs/showdown/tree/legacy).
+
+
 ## Quick Example
 
 ### Node