Update README.md

Author: yushulx

examples/9.x/gradle_kotlin/README.md

@@ -13,4 +13,7 @@ To build and run the barcode reader, use the following command:
 
 ```bash
 ./gradlew run --args="<image file> <license file>"
-```
+```
+
+## Blog
+- [How to Build Desktop Barcode Scanner in Java and Kotlin](https://www.dynamsoft.com/codepool/gradle-java-kotlin-barcode-scanner.html)