Native Distribution tutorial corrections (#72)

tutorials/Native_distributions_and_local_execution/README.md

@@ -122,7 +122,7 @@ compose.desktop {
             packageName = "ExampleApp"
             version = "0.1-SNAPSHOT"
             description = "Compose Example App"
-            copyright = project.file("LICENSE.txt").readText()
+            copyright = "© 2020 My Name. All rights reserved."
             vendor = "Example vendor"
         }
     }
@@ -197,6 +197,7 @@ The app icon needs to be provided in OS-specific formats:
 ```kotlin
 compose.desktop {
     application {
+        nativeDistributions {
             macOS {
                 iconFile.set(project.file("icon.icns"))
             }
@@ -207,5 +208,6 @@ compose.desktop {
                 iconFile.set(project.file("icon.png"))
             }
         }
+    }
 }
 ```