Add setup script for virtual environment

[benecke2019]

Enhance CLI documentation and improve setup script

Summary

This PR improves the Kaprese setup/installation script (setup.sh) for macOS users to ensure a smoother onboarding experience.

Changes

• Check for Python 3.12 or higher; automatically install via Homebrew if missing
• Create and activate a virtual environment (venv) automatically
• Upgrade pip, setuptools, and wheel inside the virtual environment
• Install required dependencies: docker>=6 and rich>=13
• Install the Kaprese package itself (pip install .)
• Provide clear messages and instructions for users

Usage

# Run the setup script
./setup.sh

# Activate virtual environment manually if needed
source venv/bin/activate

# Verify Kaprese installation
kaprese --help