Publish to Maven

[displague]

Follow-up to #7

This project should publish to Maven so that it can be consumed easily by Maven users and in a consistent way to how other packages from Equinix are published.

https://central.sonatype.com/search?q=equinix&smo=true (Includes non-Metal and Pulumi, others)
https://central.sonatype.com/search?q=packet&smo=true (Includes Packet Java, JCloud, others)

The Pulumi provider has a step, and GHA credentials, that make this possible:
https://github.com/equinix/pulumi-equinix/blob/main/.github/workflows/release.yml#L144-L150