This will allow us to add specific docs around building templates or day 2+ configuration in different platforms (e.g. Kubernetes, AWS, etc)

• Rename quickstarts to platforms
• Add kubernetes platform
• Update references to quickstart
  • coder/packages
  • coder/coder
  • Blogs and documentation
• coder.com
• Add "other platforms" to assure users of Coder's extensibility

The vision here is there can be nested guides under a specific platform "Kubernetes" with best practices, template guides, etc.