Added certificate manager

[danielscholl]

All Submissions:

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• [YES] Have you added an explanation of what your changes do and why you'd like us to include them?
• [YES] I have updated the documentation accordingly.
• [YES] I have added tests to cover my changes.
• [YES] All new and existing tests passed.
• [YES I have formatted the terrafrom code. (terraform fmt -recursive && go fmt ./...)

Current Behavior or Linked Issues

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Added LetsEncrypt Cert Manager to AKS

Does this introduce a breaking change?

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• [NO]

Other information

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