fix: move to flake.nix

.config/chglog/CHANGELOG.tpl.md

.config/chglog/config.yml

.devenv.flake.nix

.envrc

.gitignore

.gitlab-ci.yml

.gitlab/issue_templates/rfc.md

.gitlab/issue_templates/thoughts-and-ideas.md

documentation/manual/de/book.toml

documentation/manual/de/book/.nojekyll

documentation/manual/de/book/01-Einleitung.html

documentation/manual/de/book/02-Erste-Schritte.html

documentation/manual/de/book/404.html

documentation/manual/de/book/CNAME

...mentation/manual/de/book/FontAwesome/css/font-awesome.css

...entation/manual/de/book/FontAwesome/fonts/FontAwesome.ttf

.../manual/de/book/FontAwesome/fonts/fontawesome-webfont.eot

.../manual/de/book/FontAwesome/fonts/fontawesome-webfont.svg

.../manual/de/book/FontAwesome/fonts/fontawesome-webfont.ttf

...manual/de/book/FontAwesome/fonts/fontawesome-webfont.woff