Add $CI_PROJECT_DIR in the paths to find libraries

.gitlab-ci.yml

@@ -29,8 +29,8 @@ doxygen:
     - apk update && apk --no-cache add git doxygen graphviz ttf-freefont texmf-dist texmf-dist-latexextra texlive texlive-dvi
   script:
     - git clone --recurse-submodules https://gitlab-ci-token:${CI_JOB_TOKEN}@git.rwth-aachen.de/unicado/libraries
-    - cd libraries/aircraftGeometry2/doc/ && ( cat Doxyfile ; echo "OUTPUT_DIRECTORY = $CI_PROJECT_DIR/docs/documentation/" ) | doxygen -
-    - cd libraries/engine/doc/ && ( cat Doxyfile ; echo "OUTPUT_DIRECTORY = $CI_PROJECT_DIR/docs/documentation/" ) | doxygen -
+    - cd $CI_PROJECT_DIR/libraries/aircraftGeometry2/doc/ && ( cat Doxyfile ; echo "OUTPUT_DIRECTORY = $CI_PROJECT_DIR/docs/documentation/" ) | doxygen -
+    - cd $CI_PROJECT_DIR/libraries/engine/doc/ && ( cat Doxyfile ; echo "OUTPUT_DIRECTORY = $CI_PROJECT_DIR/docs/documentation/" ) | doxygen -
   artifacts:
     paths:
       - $CI_PROJECT_DIR/docs/documentation