Update README.md

Author: Eric Elliott

README.md

@@ -136,7 +136,8 @@ Some of these links are affiliate links, meaning that if you make a purchase, I
 * [RxJS](https://github.com/Reactive-Extensions/RxJS) Reactive extensions for JavaScript. [What's reactive?](https://medium.com/javascript-scene/the-two-pillars-of-javascript-pt-2-functional-programming-a63aa53a41a4)
 * [Page.js](https://github.com/visionmedia/page.js) Tiny client-side router, inspired by Express.
 * [Moment](http://momentjs.com/docs/) A lightweight JavaScript date library for parsing, validating, manipulating, and formatting dates.
-* [Globalize](https://github.com/jquery/globalize) i18n / translate your app for many languages and locations (locales)
+* [Globalize](https://github.com/jquery/globalize) i18n / translate your app for many languages and locations (locales).
+* [Leaflet](http://leafletjs.com/) Interactive map UIs made easy.
 * [Lusca](https://github.com/krakenjs/lusca) Secure your Express application. By the Kraken team at PayPal.
 * [Express](http://expressjs.com/) The most popular framework for Node.
 * [Stampit](https://github.com/ericelliott/stampit) Create objects from reusable, composable behaviors. Prototypal inheritance with stamps.