Add an example of creating a custom worker (#591)

Author: vicb

.changeset/serious-coats-speak.md

@@ -0,0 +1,9 @@
+---
+"@opennextjs/cloudflare": patch
+---
+
+Add an example of creating a custom worker
+
+Creating a custom worker enable adding DO, handlers (scheduled, queue, ...)
+
+closes #207, #397, #589