Add to the cart feature using firebase

[MAVRICK-1]

Pull Request: Add Cart Feature using Firebase

Description

This pull request adds a cart feature to the ONDC website using Firebase to manage the cart items.

Changes Made

• Added Firebase configuration for authentication and database.
• Implemented cart functionality including adding, removing, and updating items in the cart.
• Displayed the cart items on the UI with the ability to adjust quantities and remove items.
• Updated the UI to show a notification when items are added to the cart.

Screenshots (if applicable)

[Insert screenshots here]

How to Test

1. Clone this branch and install dependencies.
2. Set up Firebase project and add configuration details.
3. Navigate to the ONDC website and login/register.
4. Browse products and add items to the cart.
5. Verify that items are displayed in the cart and can be updated or removed.
6. Check that the cart data is persisted across sessions.

Checklist

• Code follows the project's style guidelines.
• Documentation has been updated to reflect the changes.
• Firebase security rules have been configured appropriately.

Related Issues

#11