build PDFs and HTMLs on GitLab CI/CD

• build PDFs and HTMLs on GitLab CI/CD (removed PDFs from Repo)
• on branch main also deploy all documents to GitLab pages
• provide review "app" (link into CI artifacts)

.gitlab-ci.yml

+image: asciidoctor/docker-asciidoctor:1.16
+
+stages:
+  - pages
+
+pages: &pages_job
+  stage: pages
+  only: &pages_condition
+    refs:
+      - main
+  script:
+    - asciidoctor --destination-dir=public/ *.adoc
+    - mv img/ public/img/
+    - asciidoctor-pdf --destination-dir=public/ *.adoc
+    - mv *.docx public/
+  artifacts:
+    paths:
+      - public
+  environment:
+    name: review/$CI_COMMIT_REF_NAME
+    url: ${CI_PROJECT_URL}/-/jobs/artifacts/${CI_COMMIT_REF_NAME}/file/public/index.html?job=${CI_JOB_NAME}
+
+pages_without_deployment:
+  <<: *pages_job
+  only: null
+  except:
+    <<: *pages_condition