"Release" calver, and assign it a (cal)version

[BenWiederhake]

I just tried to link to semver 2.0.0, zerover 0.0.1, and calver … well which version exactly? There are no calver versions, so it's not clear which one I'm referring to!

Feel free to just close this issue if you think this is silly, but I think it's actually reasonable to expect a versioning scheme to adhere to itself.