Initial docs setup

[thekaveman]

Follow outline in https://github.com/compilerla/template-devcontainer

Depends on #3

• mkdocs.yml, base on https://github.com/compilerla/template-devcontainer/blob/main/mkdocs.yml

• docs/ directory

• docs/requirements.txt with dependencies

  mdx_truly_sane_lists
  mkdocs==1.6.1
  mkdocs-awesome-pages-plugin
  mkdocs-macros-plugin
  mkdocs-material==9.5.44
  mkdocs-redirects
  

• docs/README.md with basic information (copy repo README for now)

• docs Compose service, starts with devcontainer, site is browsable locally

• GitHub Actions workflow publishes docs to GitHub Pages for the repo