v0.4.0

Performance Improvements:

• Optimization for V8 hidden class
• StaxXmlParserSync: unnecessary substring operations removed
• Caching entity regex for better performance
• Inline functions to reduce function call overhead

API Changes:

• Breaking: StaxXmlWriter is now async-based, synchronous version moved to StaxXmlWriterSync

Documentation & Testing:

• Added documentation using Astro Starlight
• Added several performance benchmarks

Major performance improvements and breaking changes for better async handling.