v1.20.0

Add precommit/terraform make target @Nuru (#348)

what

• Add precommit/terraform make target
• Update old pr/auto-format make target to make new terraform/precommit target
• Fix terraform/precommit target to only run once (not twice)
• Add tflint to build-harness-slim
• Move .tflint.hcl from / to /root (a.k.a. $HOME)
• Update go to 1.20.4
• Update Alpine to 3.17

why

• PR #342 claimed to add precommit/terraform target but did not
• Enable people and workflows to run formatting, tflint, and other processes locally before opening a PR
• Allow both full and slim Docker images to run precommit/terraform
• Move .tflint.hcl to where tflint expect it to be, in order to support tflint --enable-plugin=aws
• Keep frameworks up-to-date