Migrate documentation to its own repository

.editorconfig

.gitignore

.gitlab-ci.yml

LICENSE

ReadMe.md

babel.config.js

docs/account.md

docs/apis/delivery-service.mdx

docs/apis/metadata.mdx

docs/changelog.md

docs/details/authentication/cli.md

docs/details/authentication/scopes.md

docs/details/authentication/sender.md

docs/details/authentication/subscriber.md

docs/details/crypto.md

docs/details/encryption.mdx

docs/details/event-log.md

docs/details/pgp-export.md

docs/details/status.md

docs/getting-started/authentication.mdx