Add container image annotations

[DavidBoike]

Fills out the annotations at the index (top-most) level. Since Docker Hub doesn't appear to support displaying any of these yet, this just a first "good-enough" pass.

The resulting annotations from docker buildx imagetools inspect are:

  "annotations": {
    "org.opencontainers.image.authors": "Particular Software",
    "org.opencontainers.image.base.name": "mcr.microsoft.com/dotnet/aspnet:8.0",
    "org.opencontainers.image.created": "2024-06-19T17:40:18Z",
    "org.opencontainers.image.description": "ServiceControl primary instance",
    "org.opencontainers.image.documentation": "https://docs.particular.net/servicecontrol/",
    "org.opencontainers.image.revision": "7e2e444ac98ed35bfc45cb14defc8277211f4592",
    "org.opencontainers.image.source": "https://github.com/Particular/ServiceControl/tree/7e2e444ac98ed35bfc45cb14defc8277211f4592",
    "org.opencontainers.image.title": "servicecontrol",
    "org.opencontainers.image.url": "https://hub.docker.com/r/particular/servicecontrol",
    "org.opencontainers.image.vendor": "Particular Software",
    "org.opencontainers.image.version": "5.2.1-alpha.0.51"
  }