chore: add a changeset for Graphviz diagrams

Assisted-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: ovflowd

.changeset/graphviz-diagrams.md

@@ -0,0 +1,5 @@
+---
+'@doc-kit/generator-react': minor
+---
+
+Render ` ```dot ` code blocks as Graphviz diagrams when the optional `@hpcc-js/wasm-graphviz` dependency is installed, with `${light|dark}` colors rendering a diagram per color scheme.