Merge pull request #1 from yumemi-inc/update_readme

Update README

README.md

@@ -3,3 +3,10 @@
 # Setup Java - Gradle
 
 A GitHub Action that sets up a Java JDK and Gradle environment.
+It is a composite action that combines the following actions.
+
+- [actions/setup-java](https://github.com/actions/setup-java)
+- [gradle/gradle-build-action](https://github.com/gradle/gradle-build-action)
+- [yumemi-inc/problem-matchers/kotlin-gradle](https://github.com/yumemi-inc/problem-matchers/tree/main/kotlin-gradle)
+
+Simplify the setup description each time you run a Gradle command, and do not create Gradle caches by default.