docs: migrate to nuxt compatibility 4

docs/app/composables/useContentExamplesCode.ts

@@ -0,0 +1,27 @@
+const useContentExamplesCodeState = () => useState('content-examples-code', () => ({}))
+
+export async function fetchContentExampleCode (name?: string) {
+  if (!name) return
+  const state = useContentExamplesCodeState()
+
+  if (state.value[name]?.then) {
+    await state.value[name]
+    return state.value[name]
+  }
+  if (state.value[name]) { return state.value[name] }
+
+  // add to nitro prerender
+  if (import.meta.server) {
+    const event = useRequestEvent()
+    event.node.res.setHeader(
+      'x-nitro-prerender',
+      [event.node.res.getHeader('x-nitro-prerender'), `/api/content-examples-code/${name}.json`].filter(Boolean).join(',')
+    )
+  }
+  state.value[name] = $fetch(`/api/content-examples-code/${name}.json`).then((data) => {
+    state.value[name] = data
+  })
+
+  await state.value[name]
+  return state.value[name]
+}