Helm 3: Implement values.schema.json
## Summary
Helm v3 brings support for [schema files](https://helm.sh/docs/topics/charts/#schema-files) that allow maintainers to define a structure on their values. This can be done by defining a schema in the values.schema.json file.
We can implement this now, and those consumers using Helm v3+ will be able to benefit from it.
epic