PR Introduction: Unified Configuration File in TOML Format

Feature Description

Based on issue #1165, this PR introduces a unified configuration file in TOML format for the gpt-engineer project. This file will centralize various project settings, including:

• API keys for OpenAPI and model configurations
• Linting switches
• File extension settings for git filters
• Self-healing mechanism parameters (e.g., retry times)
• Additional settings suggested by the community

The configuration file will be persistent on disk and presented to users upon each application run, with an option to bypass opening the file while being notified of its existence and purpose.

Motivation and Application

The project manages configurations through multiple files, complicating maintenance and user experience. A unified configuration file will simplify management, enhance maintainability, and provide a consistent method for setting and reviewing configurations. The TOML format ensures readability and ease of use.

Implementation Plan

1. Create config.toml: Located in the project root directory, loaded at the start of gpte execution.
2. CLI Arguments: Consider moving some command-line arguments to the configuration file.
3. Use project_config.py: Adapted to parse the new configuration.
4. Update file_selector.py: Remove the part for old linting option.
5. Update steps.py: Get or set the configs in the main function when needed.
6. .....