ci(gitlab-ci): find files only for 'entr' in 'serve'

  script:

    # Prepare documentation

    - |

      ls -1 ./config/* ./docs/* ./mkdocs.yml ./README.md | entr sh ./docs/prepare.sh &

      find ./config/* ./docs/* ./mkdocs.yml ./README.md -type f | entr sh ./docs/prepare.sh &

      echo -n "${!}" >./docs/.serve.pid

      sleep 2

    # Generate documentation