templateplugin: add shadow jar task

templateplugin/build.gradle

@@ -29,7 +29,33 @@ dependencies {
 group = '${group_id}'
 version = '${version}'
 
-tasks.withType(JavaCompile) {
+tasks.withType(JavaCompile).configureEach {
 	options.encoding = 'UTF-8'
 	options.release.set(11)
 }
+
+tasks.register('shadowJar', Jar) {
+	dependsOn configurations.testRuntimeClasspath
+	manifest {
+		attributes('Main-Class': '${package}.${plugin_prefix}PluginTest', 'Multi-Release': true)
+	}
+
+	duplicatesStrategy = DuplicatesStrategy.EXCLUDE
+	from sourceSets.main.output
+	from sourceSets.test.output
+	from {
+		configurations.testRuntimeClasspath.collect { file ->
+			file.isDirectory() ? file : zipTree(file)
+		}
+	}
+
+	exclude 'META-INF/INDEX.LIST'
+	exclude 'META-INF/*.SF'
+	exclude 'META-INF/*.DSA'
+	exclude 'META-INF/*.RSA'
+	exclude '**/module-info.class'
+
+	group = BasePlugin.BUILD_GROUP
+	archiveClassifier.set('shadow')
+	archiveFileName.set("$${rootProject.name}-$${project.version}-all.jar")
+}