Create Automtion Cost Optimization Guide

Collect ideas here for the cost optimization guide:

• Consider using cheaper regions: https://cloudprice.net/gcp/regions?sortField=AveragePrice&sortOrder=true
• Consolidate resources into the same region when possible to avoid data transfer costs between regions. E.g. buckets should be located in the same region as the compute instances.
• Use bosh-lite for test environments where possible
• Automate clean up of orphaned resources like disk, images, VMs... (e.g. in https://github.com/cloudfoundry/community/issues/1185#issuecomment-3046411938)
• Use cheaper and smaller machine types for test environments: https://cloud.google.com/compute/all-pricing?hl=en
• If possible make test environments ephemeral or paused
• Remove/consolidate test cases/environments
• Trigger pipelines/jobs less frequently
• Tag your IaaS resources with BOSH tags for easier discovery with an ops file like:

- type: replace
  path: /tags?
  value:
    <tag-name>: <tag-value>

Start with the cost-saving ideas and linked GCP pricing, cloudprice.net, BOSH, and BOSH tags resources in the issue body. Organize them into a guide covering regional placement, resource sizing and cleanup, ephemeral test environments, pipeline frequency, and tagging; done means the guide presents these recommendations clearly with the relevant links and examples.