Merge pull request #3652 from madhusudan-kulkarni/patch-1

docs: replaced a dead link with a similar link from MDN docs

Author: mluukkai

src/content/1/en/part1a.md

@@ -142,7 +142,7 @@ The function is then assigned to a constant variable <i>App</i>:
 const App = ...
 ```
 
-There are a few ways to define functions in JavaScript. Here we will use [arrow functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions), which are described in a newer version of JavaScript known as [ECMAScript 6](http://es6-features.org/#Constants), also called ES6.
+There are a few ways to define functions in JavaScript. Here we will use [arrow functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions), which are described in a newer version of JavaScript known as [ECMAScript 6](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const), also called ES6.
 
 Because the function consists of only a single expression we have used a shorthand, which represents this piece of code: