Add javadoc

Author: alexeysemenyukoracle

src/jdk.jpackage/macosx/classes/jdk/jpackage/internal/model/MacApplication.java

@@ -56,6 +56,13 @@ default Path appImageDirName() {
         }
     }
 
+    /**
+     * Returns {@code true} if the application image of this application should be
+     * signed.
+     *
+     * @return {@code true} if the application image of this application should be
+     *         signed
+     */
     default boolean sign() {
         return signingConfig().isPresent();
     }