Create releases instead of tags and add the jar as binary

[PaulBoon]

As a dataverse admin responsible for deploying/configuring the external plugins I now have to clone the repo and build the jar file.
If that jar was added as binary to the release, that would make the job simpler.
Also when the maintenance is automated, scripts can download that jar from the Github repo.

[pdurbin]

Good news! We're moving the Croissant exporter to the main codebase:

• Make Croissant built-in to Dataverse (no longer an external exporter) IQSS/dataverse#12130

[PaulBoon]

@pdurbin as a 'finalization' you could make the last tag into a release and add that 0.1.6 jar for those that do not want to upgrade their Dataverse instance, but do want the new croissant.

[pdurbin]

Hmm, maybe.

As for the jar itself, you shouldn't need to build it yourself. You should be able to download it from https://repo1.maven.org/maven2/io/gdcc/export/croissant/0.1.6/