新增learn-kubernetes（https://github.com/yyong-brs/learn-kubernetes）相关文件

learn/learn-kubernetes-master/kiamol/ch21/functions/hello-kiamol/hello-kiamol.java

@@ -0,0 +1,10 @@
+package io.kubeless;
+
+import io.kubeless.Event;
+import io.kubeless.Context;
+
+public class Kiamol {
+    public String hello(io.kubeless.Event event, io.kubeless.Context context) {
+        return "Hello from chapter 21!";
+    }
+}