Add license attribution for target configuration files derived from TinyGo project:
- Document source from https://github.com/tinygo-org/tinygo/tree/release/targets
- Include complete BSD 3-Clause license from TinyGo project
- Clarify licensing terms for target configuration files
- Ensure proper attribution to TinyGo Authors and Go Authors
- Maintain compliance with original license requirements
This ensures proper license compliance when using TinyGo's target configurations
in the llgo project.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
