The internals walkthrough was folded into the main guide. See the
**How it works** section on the landing page at
<https://sidprasad.github.io/spytial-rust/>, and the
[Library API](https://sidprasad.github.io/spytial-rust/library.html) for the
entry points (`diagram`, `diagram_with_spec`, `export_json_instance`). The
generated rustdoc is at <https://docs.rs/spytial>.