tyring publish to new maven central

[atty303]

https://central.sonatype.com/publishing/namespaces
https://mill-build.org/mill/scalalib/publishing.html#_publishing_to_sonatype_maven_central

[i10416]

Hello, @atty303, I just sent a PR to update mill version for build from 0.11 to 1.0 because I believe it is much easier to publish the package to new sonatype by mill 1.0. It does not update mill version for the plugin.

#10