Documentation Update: Explaining React.memo and useMemo with Examples

[ripu2]

This pull request adds comprehensive and beginner-friendly documentation for React.memo and useMemo to enhance understanding of memoization in React. The new documentation includes:

1. Detailed explanations of what React.memo and useMemo are, their use cases, and when to apply them.
2. Practical examples demonstrating how to implement these features effectively in a React application.
3. Best practices for optimizing performance with memoization.
4. References to external resources and walkthrough videos for further learning.
5. This enhancement aims to support developers in leveraging memoization techniques to improve application performance and provide clarity on these important React features.

[filiptammergard]

Thanks for suggestion, but React.memo is not specific to React+TypeScript, so it's better to just look in the official React docs. In this project we only document things that are directly related to how to use TypeScript with React.