Add new file

.gitlab-ci.yml

+image: gitlab-registry.mpcdf.mpg.de/nomad-lab/atomic-features-package
+stages:
+  - doc_builds
+pages:
+  stage: doc_builds
+  script:
+    - cd atomic-features-package/docs/
+    - make html
+    - mv _build/html/ ../../public/
+    - cd ../../
+  artifacts:
+    paths:
+      - public
+  only:
+  - master
+  - docs
+  - joss