Fix another typo typo (#1021)

Remove duplicated word.

Related to #1007

content/docs/add-react-to-a-website.md

@@ -74,7 +74,7 @@ Open **[this starter code](https://cdn.rawgit.com/gaearon/0b180827c190fe4fd98b4c
 >
 >This code defines a React component called `LikeButton`. Don't worry if you don't understand it yet -- we'll cover the building blocks of React later in our [hands-on tutorial](/tutorial/tutorial.html) and [main concepts guide](/docs/hello-world.html). For now, let's just get it showing on the screen!
 
-After the **[the starter code](https://cdn.rawgit.com/gaearon/0b180827c190fe4fd98b4c7f570ea4a8/raw/b9157ce933c79a4559d2aa9ff3372668cce48de7/LikeButton.js)**, add two lines to the bottom of `like_button.js`:
+After **[the starter code](https://cdn.rawgit.com/gaearon/0b180827c190fe4fd98b4c7f570ea4a8/raw/b9157ce933c79a4559d2aa9ff3372668cce48de7/LikeButton.js)**, add two lines to the bottom of `like_button.js`:
 
 ```js{3,4}
 // ... the starter code you pasted ...