docs: Add English README for PySintegra with complete registry coverage

- Introduced a new English README file detailing the features and usage of the PySintegra library.
- Highlighted major updates in version 1.0.0, including complete SINTEGRA specification coverage and Pydantic model integration.
- Provided installation instructions, quick start examples, and comprehensive documentation for all registry types.
- Included advanced features such as validation, type safety, and batch processing capabilities.
- Enhanced the overall documentation to improve accessibility for English-speaking users.

This addition aims to broaden the user base and improve understanding of the library's functionalities.

Author: felps-dev