slideConfig
Configure a SlideConfig whose reveal.js data-* options (transitions, backgrounds, Markdown separators) apply to every child slide in this vertical stack via the wrapper <section>. The kslides-managed font properties (fontSize, codeFontSize, codeWrap) are not applied at the stack level — they are resolved per-slide, so set them inside each child slide's own slideConfig{} or in the presentation/global slideConfig{} instead.