Updates for v20+ and misc terraform bug fixes. Also refactored to use
terraform variables instead of locals which helps with readability and
ease of use for new users.
Terraform validation is currently passing:
Additionally added [terraform-docs](https://terraform-docs.io/) to
generate a more helpful README for terraform specific configuration.
Raw K8s manifests were updated with changes for v20+ as well.
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Co-authored-by: Félix Malfait <felix.malfait@gmail.com>
