[stdlib-js] Move jsTypeOf to a documentable source root and restore its kdoc

libraries/stdlib/js/runtime/jsIntrinsics.kt

@@ -120,10 +120,6 @@ internal fun jsBitShiftL(a: Any?, b: Any?): Int
 @JsIntrinsic
 internal fun jsInstanceOfIntrinsic(a: Any?, b: Any?): Boolean
 
-// @JsIntrinsic
-//  To prevent people to insert @OptIn every time
-public external fun jsTypeOf(a: Any?): String
-
 @JsIntrinsic
 internal fun jsNewTarget(a: Any?): Any?
 

libraries/stdlib/js/src/kotlin/core.kt

@@ -51,3 +51,11 @@ public external val definedExternally: Nothing
  *        including parameters. You can't refer to functions, properties and classes by their short names.
  */
 public external fun js(code: String): dynamic
+
+
+/**
+ * Function corresponding to JavaScript's `typeof` operator
+ */
+// @JsIntrinsic
+//  To prevent people to insert @OptIn every time
+public external fun jsTypeOf(a: Any?): String