add gitlab CI build

.ci/build_document.sh

@@ -0,0 +1,8 @@
+set -e
+echo "Building document"
+make pdf
+mkdir public
+mv 2021_Systemnahe_Programmierung.pdf public
+mv 2021_Systemnahe_Programmierung.log public
+cd public/
+tree -H '.' -I "index.html" -D --charset utf-8 -T "Systemnahe Programmierung" > index.html

.gitlab-ci.yml

@@ -0,0 +1,33 @@
+stages:
+  - build
+  - pages
+
+default:
+    tags:
+        - latex
+
+build-document:
+  stage: build
+  script:
+      - .ci/build_document.sh
+  variables:
+      GIT_SUBMODULE_STRATEGY: recursive
+  artifacts:
+    paths:
+        - public/
+  only:
+      - tags
+      - branches
+        #      - merge_requests
+
+
+pages:
+    stage: pages
+    artifacts:
+        paths:
+            - public/
+    script:
+        - echo "Deploying to pages"
+        - test -f public/2021_Systemnahe_Programmierung.pdf
+    only:
+        - master