Update README.md

Author: rcalago

core-kotlin-modules/core-kotlin-files/README.md

@@ -4,3 +4,4 @@
 - [Kotlin Path API](https://www.baeldung.com/kotlin/kotlin-path-api)
 - [Delete Files and Subdirectories in a Directory in Kotlin](https://www.baeldung.com/kotlin/delete-directories-with-contents)
 - [Convert File to Byte Array in Kotlin](https://www.baeldung.com/kotlin/file-byte-array)
+- [How to Create a Temporary File in Kotlin](https://www.baeldung.com/kotlin/temp-file)