Implemented a simple GET endpoint that returns 'Hello, World\!' message

[Valley-15]

Description

This PR implements a basic GET endpoint in the Express server that responds with a "Hello, World!" message when accessed at the root URL (/).

Changes:

• Added a simple GET route in the Express application that returns the message "Hello, World!".
• Configured the server to listen on a port defined by the .env file or default to port 3000.

How to Test:

1. Clone the repository and check out the branch feature/hello-world-endpoint.
2. Run npm install to install the dependencies.
3. Start the server by running npm start.
4. Open a browser or use curl to access http://localhost:<PORT> and verify that it returns "Hello, World!".

Additional Information:

• Make sure your .env file includes a PORT variable to specify the port on which the server will run.

Fixes:

• This PR fixes issue Create a Basic Endpoint #24.

[Valley-15]

the above shows output for the issue #24