Enhance configuration management and expand documentation

[jcp]

This PR adds a more robust configuration system with a standard naming convention. The main changes are:

• Added python-dotenv in the main __init__.py to load environment variables.
• Created a .config directory containing sample configuration files (sample-config.yaml and sample-env.env). Each includes a full list of all possible configuration options.
• Added an owl setup command to automatically generate config.yaml and .env files in the root directory. Users are prompted to provide their name, and a secure client_token is generated.
• Introduced export_config_to_env and apply_env_overrides utility functions to enhance the Configuration base model. Configuration options from the config.yaml file are exported as environment variables. The .env takes precedence.
• Minor changes and improvements to accommodate the configuration adjustments.
• Added tests to new functionality and the LLMService class.
• Expanded the documentation, including sections on getting started, server configuration, configuration options, and various installation guides.