Small punctuation typo fix (#44)

Author: danielleford04

questions/what-is-a-closure-and-how-why-would-you-use-one/en-US.mdx

@@ -65,7 +65,7 @@ console.log(counter()); // Outputs: 2
 
 ## Closures in React
 
-Closures are everywhere. Below code shows a simple example of increasing a counter on a button click. In this code, `handleClick` forms a closure. It has access to it's outer scope variable `count` and `setCount`
+Closures are everywhere. Below code shows a simple example of increasing a counter on a button click. In this code, `handleClick` forms a closure. It has access to its outer scope variable `count` and `setCount`.
 
 ```jsx
 import React, { useState } from 'react';