Update 01-introduction.md

Fixed "replacing" -> "replace".

chapters/01-introduction.md

@@ -63,7 +63,7 @@ Maturity in software (framework) development isn't simply about how long a frame
 
 Backbone provides a minimal set of data-structuring (Models, Collections) and user interface (Views, URLs) primitives that are helpful when building dynamic applications using JavaScript. It's not opinionated, meaning you have the freedom and flexibility to build the best experience for your web application how you see fit. You can either use the prescribed architecture it offers out of the box or extend it to meet your requirements.
 
-The library doesn't focus on widgets or replacing the way you structure objects - it just supplies you with utilities for manipulating and querying data in your application. Backbone also doesn't prescribe a specific template engine. While you are free to use the micro-templating offered by Underscore.js (Backbone's only hard dependency), views can bind to HTML constructed using your templating solution of choice.
+The library doesn't focus on widgets or replace the way you structure objects - it just supplies you with utilities for manipulating and querying data in your application. Backbone also doesn't prescribe a specific template engine. While you are free to use the micro-templating offered by Underscore.js (Backbone's only hard dependency), views can bind to HTML constructed using your templating solution of choice.
 
 Looking at the [large](http://backbonejs.org/#examples) number of applications built with Backbone, it's clear that it scales well. Backbone also works quite well with other libraries, meaning you can embed Backbone widgets in an application written with AngularJS, use it with TypeScript, or just use an individual class (like Models) as a data backer for simpler apps.