Fixed typo

Fixed 'referrer' typo

Author: josephharkins

5-network/06-fetch-api/article.md

@@ -52,7 +52,7 @@ Usually that header is set automatically and contains the url of the page that m
 
 **The `referrer` option allows to set any `Referer` (within the current origin) or remove it.**
 
-To send no referer, set an empty string:
+To send no referrer, set an empty string:
 ```js
 fetch('/page', {
 *!*