Update README.md

Author: jxnl

README.md

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 ## License
 
 This is educational material for the "Systematically Improving RAG Applications" course.
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-## 📧 Free Email Course
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-Want to learn more about RAG? Take our free email course and get the latest news and information about RAG techniques and best practices.
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-[**Sign up for the free RAG Crash Course →**](https://fivesixseven.ck.page/rag-crash-course){ .md-button .md-button--primary }
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-## 🚀 Ready to Systematically Improve Your RAG Applications?
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-**Join thousands of developers who are building better AI applications with our proven methodology.**
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-_Learn evaluation strategies, user experience design, and architectural patterns that actually work in production._