Currently, this plug-in is only available at BukkitDev, but we could reach more people of we would also create a page at Spigot.

I made a spigot page at https://www.spigotmc.org/resources/knokkos-custom-items.88182/ .
Unfortunately, the Editor is still awaiting moderator approval. But, since I can't do anything about that, I will close this issue.