Update article.md

Fix minor typo in Function binding article.

Author: rahulrao0209

1-js/06-advanced-functions/10-bind/article.md

@@ -125,7 +125,7 @@ funcUser(); // John
 */!*
 ```
 
-Here `func.bind(user)` as a "bound variant" of `func`, with fixed `this=user`.
+Here `func.bind(user)` is a "bound variant" of `func`, with fixed `this=user`.
 
 All arguments are passed to the original `func` "as is", for instance: