BAEL-4513 Gradle source vs target compatibility (#11762)

* Add example code for Gradle sourceCompatibility vs targetCompatibility

* Fix code format

gradle/gradle-source-vs-target-compatibility/build.gradle

@@ -0,0 +1,12 @@
+plugins {
+    id 'java'
+}
+
+description = 'gradle-source-vs-target-compatibility'
+
+group 'com.baeldung'
+
+java {
+    sourceCompatibility = "1.6"
+    targetCompatibility = "1.8"
+}

gradle/gradle-source-vs-target-compatibility/src/main/java/com/baeldung/helloworld/HelloWorldApp.java

@@ -0,0 +1,9 @@
+package com.baeldung.helloworld;
+
+public class HelloWorldApp {
+
+    public static void main(String[] args) {
+        System.out.println("Hello World!");
+    }
+
+}

gradle/settings.gradle

@@ -6,5 +6,6 @@ include 'greeter'
 include 'gradletaskdemo'
 include 'junit5'
 include 'gradle-employee-app'
+include 'gradle-source-vs-target-compatibility'
 
 println 'This will be executed during the initialization phase.'