Snippet format update

To match the starter (for the migration)

snippets/createEventHub.md

@@ -1,4 +1,7 @@
-### createEventHub
+---
+title: createEventHub
+tags: browser,event,advanced
+---
 
 Creates a pub/sub ([publish–subscribe](https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern)) event hub with `emit`, `on`, and `off` methods.
 
@@ -43,4 +46,4 @@ hub.emit('increment'); // `increment` variable is now 1
 
 // Unsubscribe: stop a specific handler from listening to the 'message' event
 hub.off('message', handler);
-```
+```