feat: pgn parser

app/build.gradle

@@ -43,16 +43,20 @@ run {
     standardInput = System.in
 }
 
+
+// Apply a specific Java toolchain to ease working on different environments.
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
 jar {
     manifest {
         attributes 'Main-Class': application.mainClass
     }
 }
 
-run {
-    standardInput = System.in
-}
-
 tasks.named('test') {
     // Use JUnit Platform for unit tests.
     useJUnitPlatform()