Code transforms

Add showJs to a TypeScript or TSX fence:

```ts showJs title="client.ts"
const answer: number = 42
```

The Vite integration transpiles the example with TypeScript and emits persistent TypeScript and JavaScript tabs. Both versions are highlighted by Shiki and use the normal copy action.

Shiki annotations

Foldocs enables line highlights, word highlights, diff lines, focus, and error/warning notation through the official Shiki transformers. Consecutive code fences with tab="Label" are grouped automatically.

Custom highlighter

Use highlightCode for Twoslash or a project-specific highlighter. It receives the source, language, metadata, and file path at build time.