Merge pull request #6576 from yuji0602/tutorial_md_sample_json_change

Changed example json value.
(cherry picked from commit ec036ed1851bdb7937e9c47c678d4882643fd336)

docs/tutorial.md

@@ -380,8 +380,8 @@ When the component is first created, we want to GET some JSON from the server an
 
 ```json
 [
-  {"author": "Pete Hunt", "text": "This is one comment"},
-  {"author": "Jordan Walke", "text": "This is *another* comment"}
+  {"id": "1", "author": "Pete Hunt", "text": "This is one comment"},
+  {"id": "2", "author": "Jordan Walke", "text": "This is *another* comment"}
 ]
 ```