Update CI/CD docs

[bourgeoisor]

This PR:

• Updates the CI/CD pipeline doc and moves it to the docs/ directory (before / after)
  • Expanded and cleaned up the context
  • Cleaned up the steps
• Updates the root README and move it back to the root (before, after)
  • Fixed typo in the quickstart (stray --region)
  • Expanded the "docs" section at the bottom
• Creates a "directory" of docs as a README of docs/ (here)
• Creates a "directory" of IaC as a README of iac/ (here)
• Hardcodes the TF state bucket name to simplify the set-up process

Because of the same-name files that moved around, the "GitHub diff" is moot. See above the before / after links as well as "what" changed, which can help with the review.

[minherz]

lgtm. I did not validate the content and/or links.