Code Review follow up tasks

[jmound]

• Call out that environment (prod v non-prod) are not considered in this demo #61
• Consider creating a “Known Issues” / “Gotcha” section in documentation. ie. That forsetti needs to be created before some variables can be set and re-applied #61
• Review for consistency with Google’s internal terraform standards guide #62
• in shared.tf, separate out variables and locals into separate files
• where applicable, like where there are long service account names, use locals. Example #63
• Ensure commented descriptions on all IAM bindings #55
• Migrate to use CFT log-export module #54
• Remove unused cluster outputs #53

[chroto]

@jmound I'm starting from bottom and assigning myself some of these tasks to work on

#53 , #54 , #55

[jmound]

@chroto and I further discussed breaking shared.tf in to two separate files. Doing so will require the addition of a new symlink in each project and component directory. The conclusion was that the complexity outweighs the benefit, and it's somewhat easily changed if/when required.