[Build] Add imgui-app javadoc to release

imgui-app/build.gradle

@@ -43,6 +43,11 @@ task sourcesJar(type: Jar, dependsOn: classes) {
     from sourceSets.main.allSource
 }
 
+task javadocJar(type: Jar, dependsOn: javadoc) {
+    archiveClassifier.set('javadoc')
+    from javadoc.destinationDir
+}
+
 publishing {
     publications {
         MyPublication(MavenPublication) {
@@ -50,6 +55,7 @@ publishing {
             groupId 'io.imgui.java'
             artifactId 'imgui-java-app'
             artifact sourcesJar
+            artifact javadocJar
             version property('version')
         }
     }