v0.1.1 - Stable release with comprehensive XSD validation features

✅ Core Features:
- Complete XSD parsing and validation
- All content models: xs:sequence, xs:choice, xs:all
- Full attribute validation (required, optional, fixed, default)
- Comprehensive occurrence constraints (minOccurs, maxOccurs, unbounded)

✅ Advanced XSD Support:
- xs:import and xs:include with circular reference protection
- Enhanced namespace support with qualified element handling
- 20+ XML Schema built-in types (integers, decimals, dates, URIs, binary)
- Pattern validation with regex support
- Length and numeric range constraints
- Enumeration validation

✅ API & Developer Experience:
- Unified ParseXSD() API - automatically handles imports/includes
- Detailed validation error messages with element context
- Pure Go implementation - no CGO dependencies
- Comprehensive test coverage (43 test cases)
- Complete documentation with examples

✅ Performance & Reliability:
- Internal lookup maps for O(1) type resolution
- Streaming XML parser with minimal memory allocation
- Circular dependency detection and prevention
- Thorough error handling and validation

This release represents a complete, production-ready XML Schema validation library.

init: XML schema validation in pure go

init: XML schema validation in pure go