Implement a more robust way of writing parameters.yaml

We currently use string replacement in parameters-template.yaml (e.g. {{SCENARIO_PROPERTIES}}), which preserves comments but lacks structure and validation.

Recommended options:
Use yaml (eemeli/yaml) AST library ✅

Preserves comments and formatting

Allows programmatic injection of schema blocks

Supports attaching inline comments via commentBefore

Use Handlebars templates 🟡

Preserves surrounding comments

Good for injecting dynamic blocks

Less robust for nested YAML editing

Use a parallel .comments.md or .yaml.comments.json file 🟢

Separates logic and documentation

Useful if generating OpenAPI for both code and docs

✳️ Recommended: Switch to the yaml library for AST-based injection while preserving comments inline.