Migrate examples to new JS plugin

    * General cleanup and TODOs

Co-authored with: ilya.goncharov@jetbrains.com
diff --git a/buildSrc/src/main/kotlin/Platform.kt b/buildSrc/src/main/kotlin/Platform.kt
index 4cacd9e..b667a13 100644
--- a/buildSrc/src/main/kotlin/Platform.kt
+++ b/buildSrc/src/main/kotlin/Platform.kt
@@ -1,5 +1,6 @@
 import org.gradle.api.Project
 
+// Use from Groovy for now
 fun platformOf(project: Project): String =
     when (project.name.substringAfterLast("-")) {
         "js" -> "js"