docs: improve README formatting and header spacing

Created a professional README.md for the Discount Calculator script, including how it works, example output, license, author info, and file listing.

Author: augusto-mate

README.md

@@ -1,2 +1,32 @@
-# python-week-3-assignment
-Assignment documentation and releases.
+# 💸 Discount Calculator
+
+This Python script calculates the final price of an item after applying a discount — but only if the discount is **20% or more**.
+
+## 🚀 How It Works
+
+1. User enters the original price and discount percentage
+2. If the discount is **>= 20%**, it's applied
+3. Otherwise, the original price is returned
+4. Invalid input is handled gracefully
+
+## 💡 Example Output
+
+Enter the original price: 100  
+Enter the discount percentage: 25  
+Discount applied! Final price: $75.00
+
+Enter the discount percentage: 15  
+No discount applied. Final price: $100.00
+
+## 📂 Files
+
+- `discount_calculator.py`: Core script
+
+## 👨‍💻 Author
+
+Augusto Mate  
+📧 mate.augusto.mz@gmail.com
+
+## 🪪 License
+
+This project is licensed under the [MIT License](LICENSE).