Fix semantic mistake
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.
greg-dev/clean-code-javascript-pl,ryanmcdermott/clean-code-javascript,HemantPawar/clean-code-javascript,DavidVujic/clean-code-javascript,ChrisNikkel/clean-code-javascript,andersontr15/clean-code-javascript-es,chux0519/clean-code-javascript