Indeed. It seems these are kind of symbolic links, the files are rather small, but given the cluster size of NTFS, the initial 1 MB is multiplied to occupy 20 MB of disk space... Of which we have no usage on Windows and probably not on Linux as well.
It is trivial to delete the folder, it is better not to include it.
Thanks for pointing this out, we'll try to take better care in the future.
The initial release was made and uploaded to maven central, and the zip available from the download page was to be based on that. However, shortly after the central sync was complete, an error was discovered - the release notes had a few extra entries that were not actually released yet. The change was made by hand, since the zip couldn't be auto-generated for release again - maven releases, once made, can't be rescended. This hand-modified zip, made on a Mac, was uploaded instead to the downloads page.