v1.2.0

feat: Enhance schema definition and validation features

- Added `required` field to `FieldConfig` for clarity in schema definitions.
- Updated `keys` and `values` in `FieldConfig` to accept functions for more flexibility.
- Introduced `Union` function for creating union types in schemas.
- Improved type inference for nested structures and simplified optional/required key handling.
- Enhanced validation logic in `Base` class to support new schema features.
- Updated benchmarks to reflect new validation scenarios and improved performance metrics.
- Refactored example files to demonstrate new features and best practices.
- Added TypeScript definitions for example files.
- Updated package metadata for versioning and repository links.