Refactor documentation to highlight differences and similarities between various cloud environments that Compliant Kubernetes supports

[cristiklein]

Instead of having 1 documentation per supported cloud provider, it would be great to focus on commonalities and differences. We should use Content tabs.

[tordsson]

[] https://compliantkubernetes.io/operator-manual/aws/ [] https://compliantkubernetes.io/operator-manual/exoscale/

[cristiklein]

Moving forward, please do the following when adding new documentation to reduce unnecessary differences:

vimdiff docs/operator-manual/exoscale.md docs/operator-manual/azure.md

[cristiklein]

We removed the provider-specific instructions and instead have a template that we need to specialize for each on-prem installation. I'm closing this issue, since it is not relevant now. We'll reopen it if it becomes relevant in the future.