implement automatic help

src/commonMain/kotlin/com/infendro/cli/command/context/Context.kt

@@ -10,8 +10,8 @@ import kotlin.reflect.KProperty
 class Context internal constructor(
     val command: Command,
     val commands: List<Cmd>,
-    val options: List<Opt>,
     val arguments: List<Arg>,
+    val options: List<Opt>,
 ) {
     class Cmd(
         val name: String,
@@ -28,6 +28,10 @@ class Context internal constructor(
 
     internal fun execute() = (command.execute)()
 
+    fun help() {
+        command.help?.let { println(it) }
+    }
+
     operator fun Command.Key.getValue(thisRef: Any?, property: KProperty<*>): String = commands[index].name
 
     private val <T : Any> Argument<T>.index: Int