Your first diagram

The editor is meant to play a role similar to Swagger Editor: author the source, validate it quickly, and learn the notation through immediate feedback.

1. run npm install
2. run npm run dev:editor
3. pick one of the built-in fixtures
4. choose the layer you want to inspect
5. preview the current rendering output while refining the notation
6. if the model is invalid, review the structured validation issues shown by the editor

The editor also performs live validation while you type, even before rendering.