Docs: Align Server .env.example with README

[Git-brintsi20]

Hey @manishkumar8312

Description

There is a discrepancy between the server environment variables listed in the main README.md and the variables present in the server/sample.env file.

The README.md correctly lists the following Cloudinary variables as required:

• CLOUDINARY_CLOUD_NAME
• CLOUDINARY_API_KEY
• CLOUDINARY_API_SECRET

However, these variables are missing from server/sample.env. This can cause confusion for new contributors during setup.

Proposed Solution

Update server/sample.env to include the missing Cloudinary variables with placeholder values. This will ensure the example file is a complete and accurate template.