docs: fix grammar, terminology, and punctuation in README template

[SoumyaRaikwar]

This PR updates the README template to fix grammar and terminology issues.
Changes:

• Corrected "recommend to using" → "recommend using"
• Changed "healthcheck" to "health check" for consistency with Kubernetes docs
• Added clarity to CPU limits guidance
• Expanded "NS" to "namespaces" for readability

[k8s-ci-robot]

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[mrueg]

@SoumyaRaikwar why did you close this PR?