modified .env.example,.gitignore,app.js

[VarnitRaina]

Summary
This pull request includes several improvements and fixes to enhance the functionality and maintainability of the application. Key changes include the addition of the uploads directory to .gitignore, improvements to the MongoDB connection handling, and updates to the rate limiter configuration.

Changes Made
Updated .gitignore:

Added the uploads/ directory to the .gitignore file to prevent uploaded files from being tracked in the repository.
Improved MongoDB Connection Handling:

Enhanced the MongoDB connection logic in app.js to include more informative console messages on connection success and error handling. This provides better visibility into the application’s status during development.
Increased Rate Limiter Configuration:

Adjusted the rate limiter settings to allow for increased requests per time window, improving the application's ability to handle traffic and reducing the likelihood of request throttling.
Additional Code Refactoring:

Made minor adjustments and optimizations in app.js for better readability and performance.

[sravanth-space]

LGTM

[YasharF]

These changes are not needed, they break the build.