replace starry-night with shiki

.changeset/kind-islands-smell.md

@@ -0,0 +1,5 @@
+---
+"mdxts": patch
+---
+
+Replace starry-night with shiki.

mdxts/components/SiblingNavigation.tsx

@@ -1,6 +1,37 @@
 import * as React from 'react'
-import { getPathData } from '../utils'
 
+/** Returns the active and sibling data based on the active pathname. */
+export function getPathData(
+  /** The collected data from a source. */
+  data: Record<string, any>,
+
+  /** The pathname of the active page. */
+  pathname: string[]
+) {
+  const allData = Object.values(data) as any[]
+  const index = Object.keys(data).findIndex((dataPathname) =>
+    dataPathname.includes(pathname.join('/'))
+  )
+
+  function getSiblingPath(startIndex: number, direction: number) {
+    const siblingIndex = startIndex + direction
+    const siblingPath = allData[siblingIndex]
+
+    if (siblingPath?.pathname === null) {
+      return getSiblingPath(siblingIndex, direction)
+    }
+
+    return siblingPath || null
+  }
+
+  return {
+    active: allData[index] || null,
+    previous: getSiblingPath(index, -1),
+    next: getSiblingPath(index, 1),
+  }
+}
+
+/** Renders previous and next links. */
 export function SiblingNavigation({
   data,
   pathname,