Fix .gitlab-ci.yml

1 job for documentation in 5 seconds (queued for 2 seconds)
Status Name Job ID Coverage
failed pages #75552


Name Stage Failure
pages Deploy
Skipping Git submodules setup
Executing "step_script" stage of the job script
$ rm -rf public
$ mkdir public
$ mkdir -p public/doc
$ mkdir -p public/images/
$ cp -r docs/_build/html/* public/doc/
cp: cannot stat 'docs/_build/html/*': No such file or directory
ERROR: Job failed: exit code 1