Expose all public APIs

[smorimoto]

Before

export {
  BuildTarget,
  Manifest,
  Package,
  PackageCache,
  Snapshot,
  submitSnapshot
}

After

export {
  BuildTarget,
  type DependencyRelationship,
  type DependencyScope,
  type Detector,
  type Job,
  Manifest,
  Package,
  PackageCache,
  Snapshot,
  jobFromContext,
  shaFromContext,
  submitSnapshot
}

[febuiles]

Thank you!