add default eventbus

Author: ct-mbaumann

manifests/workflows/eventbus-default.yaml

@@ -0,0 +1,9 @@
+apiVersion: argoproj.io/v1alpha1
+kind: EventBus
+metadata:
+  name: default
+  namespace: events
+spec:
+  nats:
+    native:
+      replicas: 1