Version 0.2.0a3

Fix detection of prerelease

Use ${{ github.event.release.prerelease }} instead

Version 0.2.0a2

v0.2.0-alpha.2

Debug output for workflow

Version 0.2.0a1

If all goes well, the release should trigger the build of a docker file with the correct tags. The deployment should soon be available at dev.gewaessercampus.de.