Add MIT License and Improve Documentation

[Zaykus]

Add MIT License and Improve Documentation

Summary

This PR adds proper open-source licensing and significantly improves the project documentation for better accessibility and user experience.

Changes Made

🔓 License Addition

• Added MIT License to make the project properly open-source
• Without a license, the repository was essentially private/proprietary by default
• MIT License allows free use, modification, and distribution while requiring attribution

📚 Documentation Improvements

• Fixed internal navigation: Changed external GitHub links to internal anchors (e.g., #betterpayableupgrade)
• Grammar and language fixes: Corrected typos, improved sentence structure, and standardized terminology
• Enhanced formatting: Better table alignment, consistent heading hierarchy, and improved readability
• Structural improvements: Clearer section organization and better list formatting

Why These Changes Matter

• Legal clarity: The MIT License ensures developers can safely use and contribute to the project
• Better UX: Internal links keep users in our documentation instead of redirecting to external repos
• Professionalism: Improved grammar and formatting make the project more credible and accessible
• Community friendly: Clear licensing encourages contributions and adoption

Testing

• ✅ All internal links navigate correctly within the document
• ✅ Documentation formatting renders properly on GitHub
• ✅ MIT License is properly recognized by GitHub

This PR transforms the repository from a technically private/unlicensed state to a fully open-source project with professional documentation.