Update article.md

object constructor -> the object's constructor

Author: paroche

1-js/09-classes/05-extend-natives/article.md

@@ -21,7 +21,7 @@ alert(filteredArr); // 10, 50
 alert(filteredArr.isEmpty()); // false
 ```
 
-Please note a very interesting thing. Built-in methods like `filter`, `map` and others -- return new objects of exactly the inherited type `PowerArray`. Their internal implementation uses object `constructor` property for that.
+Please note a very interesting thing. Built-in methods like `filter`, `map` and others -- return new objects of exactly the inherited type `PowerArray`. Their internal implementation uses the object's `constructor` property for that.
 
 In the example above,
 ```js