Add hello world examples

Author: seabaylea

README.md

@@ -5,17 +5,63 @@ WARNING: Work in Progress (WIP) not ready for production
 
 The runtime provides Kotlin running on Java 8u131 b11.
 
+## Hello World Kotlin Action
+
+The runtime for Kotlin supports two types of API for creating actions:  
+1. JSON parameter and return type, using the GSON Library.  
+2. Data Class parameter and return type.
+
+### JSON parameter based main.kt
+The following shows how to build a "HelloWorld" action using JSON parameters:
+
+```kotlin
+import com.google.gson.JsonObject
+
+fun main(args: JsonObject) : JsonObject {
+    val name = args.getAsJsonPrimitive("name").getAsString();
+    val hello = JsonObject();
+    hello.addProperty("greeting", "Hello " + name + "!");
+    return hello
+}
+```
+The action can then be compiled into a JAR file for use with the runtime for Kotlin. As the action has a dependency on the [Google GSON library](https://github.com/google/gson), it needs to be available on the classpath:
+```sh
+kotlinc -classpath ./gson-2.6.2.jar main.kt -d myAction.jar
+```
+
+### Data Class based main.kt
+The following shows how to build a "HelloWorld" action using JSON parameters:
+
+```kotlin
+data class User (
+    val name: String
+)
+
+data class Hello (
+    val greeting: String
+)
+
+fun main(user: User) : Hello {
+    val hello = Hello("Hello " + user.name + "!")
+    return hello
+}
+```
+The action can then be compiled into a JAR file for use with the runtime for Kotlin as follows:
+```sh
+kotlinc hello.kt -d myAction.jar
+```
+
 ### How to use as a docker Action
 To use as a docker action
 
 ```sh
-bx wsk action update myAction myAction.py --docker ibmfunctions/action-kotlin
+bx wsk action update myAction myAction.jar --docker ibmfunctions/action-kotlin
 ```
 
 This works on any deployment of Apache OpenWhisk or IBM Cloud Functions
 
 ### Future: IBM Cloud Functions (based on Apache OpenWhisk)
-To use as a Kotlin kind action
+To use as a Kotlin kind action:
 
 ```sh
 bx wsk action update myAction myAction --kind kotlin