Add embedded documentation (user guide)

.gitignore

.gitlab-ci.yml

README.md

ldvspec/Dockerfile

ldvspec/docker/docker-compose-dev-cd.yml

ldvspec/docker/docker-compose-production-cd.yml

ldvspec/documentation/.gitignore

ldvspec/documentation/babel.config.js

ldvspec/documentation/docs/developer-guide/intro.md

ldvspec/documentation/docs/intro.md

ldvspec/documentation/docs/user-guide/access/_category_.json

ldvspec/documentation/docs/user-guide/access/account.md

ldvspec/documentation/docs/user-guide/access/environments.md

ldvspec/documentation/docs/user-guide/access/login.md

ldvspec/documentation/docs/user-guide/group/_category_.json

ldvspec/documentation/docs/user-guide/group/creating.md

ldvspec/documentation/docs/user-guide/group/deleting.md

ldvspec/documentation/docs/user-guide/group/editing.md

ldvspec/documentation/docs/user-guide/group/intro.md

ldvspec/documentation/docs/user-guide/intro.md