Merge branch 'fix-autobuilding' into 'master'

Fordere explizit pdflatex an

See merge request !1

.gitlab-ci.yml

@@ -3,7 +3,7 @@ image: mirisbowring/texlive_ctan_full:2019
 compiling:
   script:
       # use settings from .latexmkrc
-    - latexmk
+    - latexmk -pdf
   artifacts:
     paths:
     - "out/skript-mehrgitter-sander.pdf"