Create initial scaffold for mkdocs documentation service

[rin-skylight]

Background

Since this project provides a service to CDC developers, we want to have clear documentation that updates with each new deployment of infrastructure.

Action requested

• Add folder for documentation files
• Create initial templates for self-service and full-service docs
• Add dockerfile for the container
• Add container to CI build process

Acceptance Criteria

• Initial files should be present
• Blank site should build successfully and be published to GHCR.

Additional context

https://github.com/mkdocs/mkdocs