test: increase error path coverage for packer limits and writeFn

- Add tests for string, bin, ext, and map length limit violations
- Add tests for write functions that return short writes to ensure LengthWriting
  errors are triggered

Improve coverage for code paths not tested elsewhere

feat(msgpack): add PackerIO API for std.io interfaces

- Add PackerIO wrapper for convenient std.io.Reader/Writer support
- Add packIO() convenience function for quick packer initialization
- Add comprehensive test suite for PackerIO with 30+ test cases
- Update documentation with I/O examples, performance optimizations
- Update CI badge reference and add platform support details

Release version 0.0.15

Release version 0.0.13 - Performance optimizations and benchmark suite

Release v0.0.12: Enhanced Zig 0.16 support and improved cross-version…

… compatibility

feat(zig-compat): add compatibility layer for multiple Zig versions

- introduce compat.zig to handle differences in Zig standard library
- replace FixedBufferStream with cross-version BufferStream implementation
- support Zig 0.14.1, 0.15.1, and master versions in build and CI configurations
- update tests to use version-agnostic buffer stream methods
- add dynamic module and test creation based on Zig version

fix(test): support ArrayList API changes in Zig 0.15+

- update tests to handle allocator parameter for ArrayList in Zig 0.15+
- add conditional logic for Zig version compatibility in map-related tests
- ensure proper memory cleanup for both Zig 0.14 and 0.15+

docs(readme): update and expand documentation, add Chinese translation

- update README.md with timestamp extension support and improved usage examples
- add detailed sections for data types, timestamp usage, and error handling
- fix formatting and clarify API overview and related projects
- add README_CN.md providing a comprehensive Chinese translation of the documentation

release: `0.0.8`