Example of payload with extenstion

Signed-off-by: Fabio José <fabiojose@gmail.com>

examples/payload/v02/structured-event-1.json

@@ -0,0 +1,14 @@
+{
+  "specversion":"0.2",
+  "type":"com.github.pull.create",
+  "source":"https://github.com/cloudevents/spec/pull/123",
+  "id":"45c83279-c8a1-4db6-a703-b3768db93887",
+  "time":"2019-06-21T17:31:00Z",
+  "contenttype":"application/json",
+  "data":{
+    "much":"wow"
+  },
+  "my-extension" : {
+    "some" : "thing"
+  }
+}