metal-stack v1.0.0

See original release note at https://github.com/metal-stack/releases/releases/tag/v1.0.0

After seven years of production, and with the core components of metal-stack finally migrated to API V2, we would like to mark this stage as v1.0.0.

Please find the blog post about the release on https://metal-stack.io/.

Thanks everyone who uses and contributes to metal-stack! 🍻