add example and automation test for "Support rate-limiting for ingress-resources"

[vepatel]

Add automation tests and example for feature linked below:
Issue: #4603
Refer: https://github.com/nginxinc/kubernetes-ingress/blob/main/tests/suite/test_rl_policies.py, https://github.com/nginxinc/kubernetes-ingress/tree/main/tests/data/rate-limit

[github-actions]

Hi @vepatel thanks for reporting!

Be sure to check out the docs and the Contributing Guidelines while you wait for a human to take a look at this 🙂

Cheers!