Adding more k8s fields to the pydantic schema, including InitContainers & VolumeMounts.
helm lint + bk
we shouldn't be adding fields to these classes - the point is that they exactly match the kubernetes object that they represent (as expressed through schema extra)
Decided to refrain from schema_extra here since InitContainer isn't supported by the JSON schema API we use - was thinking about trying to hand-roll some validation hooks to show the difference between this and Container but to keep things simple decided to just provide these fields for now.
Looks like they type InitContainer as Container in https://kubernetesjsonschema.dev/v1.15.0/_definitions.json - let's just use Container as the schema for InitContainer to keep it simple.