chore: Update launch_venv_shell function

[jzombie]

• Modified the launch_venv_shell function to include the virtual environment name, 'pipper', Python version, and the full directory path in the Bash prompt.
• Added a custom greeting that displays when the shell is created.
• Ensured that the greeting only displays once when the shell is created.
• Included line breaks in the custom greeting for improved formatting.