Example for structured with extension

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

examples/express-ex/README.md

@@ -10,6 +10,8 @@ npm start
 
 __A Structured One__
 
+> Payload [example](../payload/v02/structured-event-0.json)
+
 ```bash
 curl -X POST \
      -d'@../payload/v02/structured-event-0.json' \
@@ -17,6 +19,17 @@ curl -X POST \
      http://localhost:3000/
 ```
 
+__A Structured One with Extension__
+
+> Payload [example](../payload/v02/structured-event-1.json)
+
+```bash
+curl -X POST \
+     -d'@../payload/v02/structured-event-1.json' \
+     -H'Content-Type:application/cloudevents+json' \
+     http://localhost:3000/
+```
+
 __A Binary One__
 
 ```bash