Update README.md

Author: Timer

packages/react-scripts/template/README.md

@@ -1236,7 +1236,7 @@ it('sums numbers', () => {
 ```
 
 All `expect()` matchers supported by Jest are [extensively documented here](https://facebook.github.io/jest/docs/en/expect.html#content).<br>
-You can also use [`jest.fn()` and `expect(fn).toBeCalled()`](http://facebook.github.io/jest/docs/expect.html#tohavebeencalled) to create “spies” or mock functions.
+You can also use [`jest.fn()` and `expect(fn).toBeCalled()`](https://facebook.github.io/jest/docs/en/expect.html#tohavebeencalled) to create “spies” or mock functions.
 
 ### Testing Components