Update dependencies to smbus2 and fix incorrect git clone URL in README

[mishave]

Summary

This PR addresses documentation errors and updates dependencies to improve installation reliability.

Issues Addressed

1. Incorrect repository URL - Installation instructions referenced DFRobot_GP8302 instead of DFRobot_GP8403
2. Outdated dependency - Code used unmaintained smbus library instead of current smbus2
3. Missing environment setup - No virtual environment instructions provided

Changes

• Corrected git clone URL in installation documentation
• Updated import statement to use smbus2 instead of smbus
• Added virtual environment setup instructions

Rationale

smbus2 is the actively maintained successor to smbus, providing improved Python 3 compatibility while maintaining API compatibility. Virtual environment setup prevents dependency conflicts and follows Python best practices.

Migration

Users should install smbus2 instead of smbus. Updated import to smbus as smbus

Testing

Verified functionality on Raspberry Pi 4 and 5 with provided examples.