Deprecate kubeaudit

[dani-santos-code]

Context

We should consider deprecating kubeaudit since Shopify's team hasn't been able to keep up with maintenance and cannot currently be efficient stewards.

We believe kube-bench is a good successor.

Tasks

• [x] update README mentioning that the project isn't maintained and mention an alternative (kube-bench). Make changes to Issues and PR templates
• [x] update the code to add warnings (help + running with flags)
• [x] make a new and last release
• [x] set up an announcement in Discussions
• [ ] finally archive the repo by the due date agreed on (October 2024)