Review the deliberate CLI implementation in src/deliberate/cli.py and improve the help text and documentation.

Specifically:
1. Review all command help strings (for `run`, `init`, and `validate` commands)
2. Review all option help strings to ensure they are clear and concise
3. Improve the main app-level help text
4. Add any missing documentation for important features
5. Ensure the help text follows typer/CLI best practices

Focus on making the help text more user-friendly and informative for developers who are new to the tool.

Make your changes directly to src/deliberate/cli.py and provide a clear summary of what you improved.
