Adds java version to gradle config so it automatically downloads.

README.md

@@ -19,3 +19,5 @@ NOTES:
 
 See [CONTRIBUTING.md](CONTRIBUTING.md) for development environment setup instructions.
 
+Tooling note:
+* Gradle is configured with Java Toolchains and will automatically download a Java 21 JDK when needed during builds.

gradle.properties

@@ -1,2 +1,3 @@
 version=0.2.2-SNAPSHOT
+org.gradle.java.installations.auto-download=true
 

settings.gradle

@@ -1 +1,5 @@
+plugins {
+	id 'org.gradle.toolchains.foojay-resolver-convention' version '0.9.0'
+}
+
 rootProject.name = 'ScoreKeeper'