Update Project Structure in README.md

[dimpal-yadav]

Description:
The current README.md file does not provide a clear overview of the project’s structure. Adding a dedicated Project Structure section will help new contributors and developers understand the organization of the project quickly.

Proposed Changes:
Add a 🗂️ Project Structure section in README.md.
Format it using Markdown for clarity and readability.

Benefits:
Improves documentation quality.
Helps new contributors navigate the project easily.
Makes onboarding faster for developers and collaborators.