Research values.schema.json

Summary

As part of &8, we need to understand how schema files work within Helm 3. We need to know how to implement them (with at least one minor example), and link developer documentation. We also need to understand which items should be included at the chart level, and which at the global level, or both.

• Research & demo a schema file for one of the charts
• Add appropriate additional documentation to
  • development documentation
  • CONTRIBUTING