This PR includes various documentation improvements:
- Fix grammar in README.md introduction
- Update Node.js version references to consistently indicate 'Node.js 20
or higher'
- Enhance macOS installation and setup guide with detailed instructions
- Fix broken link in API.md
- Fix formatting inconsistencies in WhatIsCompilerExplorer.md
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude <noreply@anthropic.com>