adds .gitlab-ci.yml

1 job for master in 17 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Test
failed pages #10276
doxygen

00:00:17

 
Name Stage Failure
failed
pages Test
6) Use doxygen to generate a rtf extensions file
RTF: doxygen -e rtf extensionsFile

If -s is specified the comments of the configuration items in the config file will be omitted.
error: configuration file doc/Doxyfile not found!
If configName is omitted `Doxyfile' will be used as a default.

-v print version string
ERROR: Job failed: exit code 1