Added files for Gitlab pages

gitlab-ci.yml

+image: python:3.8-buster
+
+before_script:
+  - pip install -r requirements.txt
+
+test:
+  stage: test
+  script:
+  - mkdocs build --strict --verbose --site-dir test
+  artifacts:
+    paths:
+    - test
+  rules:
+    - if: $CI_COMMIT_REF_NAME != $CI_DEFAULT_BRANCH
+
+pages:
+  stage: deploy
+  script:
+  - mkdocs build --strict --verbose
+  artifacts:
+    paths:
+    - public
+  rules:
+    - if: $CI_COMMIT_REF_NAME == $CI_DEFAULT_BRANCH

requirements.txt

+# Documentation static site generator & deployment tool
+mkdocs>=1.1.2
+
+# Add your custom theme if not inside a theme_dir
+# (https://github.com/mkdocs/mkdocs/wiki/MkDocs-Themes)
+#  mkdocs-material>=5.4.0