Support jobs in that are nested in ItemGroups.
Fix various broken images

* Fix various image urls that were not changed when the artifactid of the project was changed.
* Update readme accordingly
Merge pull request #6 from Jotschi/fix-broken-urls

Fix various broken images
Merge pull request #3 from FrantaM/folders

Support jobs that are nested in ItemGroups.
Update CHANGELOG.md
[maven-release-plugin] prepare release gitlab-plugin-1.0.8