Added new JavaScript questions to README

[Jenesh18]

This pull request enhances the repository by adding new JavaScript interview questions and their solutions to the README file. Specifically, the following updates were made:

1. Added a detailed explanation of module scope in JavaScript, including examples and key features.
2. Followed the existing repository's structure and formatting for consistency.
3. Ensured the new content adds value for users preparing for JavaScript interviews

[Jenesh18]

Hi @avrame @ckpinguin @lliccien @avalla,
I hope you're doing well! I wanted to kindly follow up on this PR. Please let me know if there's anything I can improve or if additional details are needed. Looking forward to your feedback! 😊
Thank you for your time and effort in maintaining this project.

[sudheerj]

@Jenesh18 It seems you are trying to access 'privateVariable' instead 'publicFunction' from moduleA. BTW, you are not using publicFunction anywhere in moduleB

[Jenesh18]

Hi @sudheerj, I’ve updated the answer based on your feedback. The incorrect reference to privateVariable has been removed, and the usage of publicFunction has been added in the example. and I created a new PR Please review it when you get a chance. Thanks for your time!