Added full docstrings for all public methods

[sn]

This pull request adds comprehensive docstrings to the public API of the nitro_img library, significantly improving its documentation and usability for developers. The changes clarify the behavior, parameters, return values, and usage examples for classes, methods, and exceptions throughout the codebase. Additionally, the project version is incremented to reflect these enhancements.

The most important changes are:

Batch Processing Documentation Improvements:

• Added detailed docstrings to the BatchImage class and all its public methods in batch.py, including usage examples, parameter explanations, and return value descriptions. This provides clear guidance on how to use batch image processing features. [1] [2] [3] [4]

Configuration and Error Handling Documentation:

• Enhanced the Config class in config.py with a comprehensive class-level docstring and detailed method documentation, explaining configuration options and how to update them. [1] [2]
• Expanded docstrings for all custom exception classes in errors.py, describing when each error is raised and its intended usage.

Presets and Utility Documentation:

• Improved documentation for the Presets class and its methods (thumbnail, avatar, etc.) in presets.py, including parameter details, return values, and code examples for common image tasks. [1] [2] [3]

Version Bump:

• Updated the project version from 1.0.1 to 1.0.2 in both pyproject.toml and __init__.py to reflect these documentation improvements. [1] [2]