Validate a template file against the markermd JSON Schema
validate_template_file.RdStructurally validates a template YAML (or JSON) file against the bundled
JSON Schema (inst/schema/markermd-template.json). This is an optional check
aimed at tooling and LLM-generated files; the authoritative validation
happens via the S7 constructors in read_template_yaml(). Requires the
suggested jsonvalidate package.
Value
TRUE when the file conforms to the schema, otherwise FALSE with
the validation errors attached as attributes (see jsonvalidate::json_validate()).