Update Docs / Misc Refinements

Fleshed out Documentation

alpine.conf

• improve motd readability
• default access = public
• default regions = all
• remove version 3.11 (EOL)

alpine-testing.conf

• access is private
• limit aws regions

build

• improve/refine overlay installation
• rename "actions" step to "state"

image_configs.py

• target step "state" updates images.yaml as if "publish" WOULD be done (but won't be)