KEP update to extend the Pod Failure Policy guide for FailIndex (#4779)

* KEP update to extend the Pod Failure Policy guide for FailIndex

* Apply suggestions from code review

Fixes for nits

Co-authored-by: Maciej Szulik <[email protected]>

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Co-authored-by: Maciej Szulik <[email protected]>

Author: mimowo

keps/sig-apps/3850-backoff-limits-per-index-for-indexed-jobs/README.md

@@ -777,6 +777,8 @@ in back-to-back releases.
 
 - Address reviews and bug reports from Beta users
 - Write a blog post about the feature
+- Revisit extending the [hands-on guide for Pod failure policy](https://kubernetes.io/docs/tasks/job/pod-failure-policy/)
+  to use `FailIndex`
 - Graduate e2e tests as conformance tests
 - Lock the `JobBackoffLimitPerIndex` feature gate
 - Declare deprecation of the `JobBackoffLimitPerIndex` feature gate in documentation