Fix semantic mistake

The original phrase "As stated in the Gang of Four..." is semantically incorrect.
- The "Gang of Four" is a group of authors: Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides.
- They wrote a famous book: Design Patterns.
- Here, Ryan McDermott is referring to the software-design principle "you should prefer composition over inheritance."
- This principle was stated in the book, Design Patterns.
- It was not stated in the Gang of Four -- the authors themselves.

Author: b0yfriend

README.md

@@ -1579,7 +1579,7 @@ let car = new Car()
 **[⬆ back to top](#table-of-contents)**
 
 ### Prefer composition over inheritance
-As stated famously in the [Gang of Four](https://en.wikipedia.org/wiki/Design_Patterns),
+As stated famously in [*Design Patterns*](https://en.wikipedia.org/wiki/Design_Patterns) by the Gang of Four,
 you should prefer composition over inheritance where you can. There are lots of
 good reasons to use inheritance and lots of good reasons to use composition.
 The main point for this maxim is that if your mind instinctively goes for