Merge pull request #5159 from kubernetes-sigs/copilot/fix-cronjob-webhook-versions-again

📖 (multiversion-tutorial): Show v2 webhook implementation alongside v1

Author: k8s-ci-robot

docs/book/src/multiversion-tutorial/webhooks.md

@@ -3,10 +3,21 @@
 Our conversion is in place, so all that's left is to tell
 controller-runtime about our conversion.
 
-## Webhook setup...
+## Webhook setup for v1...
+
+The v1 webhook handles conversion (as the hub) and provides validation/defaulting
+for the v1 CronJob format with a string-based schedule:
 
 {{#literatego ./testdata/project/internal/webhook/v1/cronjob_webhook.go}}
 
+## Webhook setup for v2...
+
+The v2 webhook provides validation and defaulting for the v2 CronJob format
+with the structured CronSchedule type. Note how the validation logic differs
+from v1 - it builds a cron expression from the individual schedule fields:
+
+{{#literatego ./testdata/project/internal/webhook/v2/cronjob_webhook.go}}
+
 ## ...and `main.go`
 
 Similarly, our existing main file is sufficient: