[DOCS] : Add folder structure and shared components description in contributing.md

[divyanshu-patil]

Description:

I recently came accross the repo to take a look at it, but i found that the documentation lacks the folder structure and the proper guidelines of the projects. i found it difficult to find the shared components and other utilities.
also there isnt much clear description about the tech stack used here like other dependencies

Expected behavior:

there should be proper documentation in CONTRIBUTING.md about the folder structure and the core utilies and shared components