KEP-3542 update ToC

Author: byako

keps/sig-node/3542-cri-image-pulling-with-progress-notification/README.md

@@ -95,6 +95,9 @@ tags, and then generate with `hack/update-toc.sh`.
       - [Integration tests](#integration-tests)
       - [e2e tests](#e2e-tests)
   - [Graduation Criteria](#graduation-criteria)
+    - [Alpha](#alpha)
+    - [Beta](#beta)
+    - [GA](#ga)
   - [Upgrade / Downgrade Strategy](#upgrade--downgrade-strategy)
   - [Version Skew Strategy](#version-skew-strategy)
 - [Production Readiness Review Questionnaire](#production-readiness-review-questionnaire)