Update helm readme and website docs

[vepatel]

Proposed changes

• Update helm docs with sections and values overwritten by release script
  Docs preview: https://deploy-preview-4476--nginx-kubernetes-ingress.netlify.app/nginx-ingress-controller/

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-3.3@5b31f15). Click here to learn what that means.
The diff coverage is n/a.

❗ Current head 54a66dc differs from pull request most recent head 3d88ae1. Consider uploading reports for the commit 3d88ae1 to get more accurate results

@@              Coverage Diff               @@
##             release-3.3    #4476   +/-   ##
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  Coverage               ?   52.08%           
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  Files                  ?       59           
  Lines                  ?    16956           
  Branches               ?        0           
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  Hits                   ?     8832           
  Misses                 ?     7825           
  Partials               ?      299           

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[jjngx]

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