Merge branch 'mdbook'

.dockerignore

.github/workflows/docker-build.yml

.github/workflows/mdbook-deploy.yml

.gitignore

.gitlab-ci.yml

Dockerfile

Gemfile

Gemfile.lock

README.md

_config.yml

_includes/footer.html

_includes/head.html

_includes/header.html

_includes/icon-github.html

_includes/icon-github.svg

_includes/icon-gitlab.html

_includes/icon-gitlab.svg

_includes/icon-twitter.html

_includes/icon-twitter.svg

_includes/image.html