refactor code and add component based architecture.

[Abhijay Jain]

Refactor codebase and use component-based architecture instead of adding whole code in a single file. Currently, the whole code is in and single file which makes the code a bit messy and confusing for new contributors.

Additional context

we can do this by making different components(ex: header component, footer component) and use them in the main code file. This makes code clean and efficient, and it also provides a better understanding of code to the new contributors.

we can also make separate CSS files for each component which provides more clarity to the new contributors.