docs(app): add copy markdown button (#4369)

docs/app/components/PageHeaderLinks.vue

@@ -0,0 +1,77 @@
+<script setup lang="ts">
+const route = useRoute()
+const toast = useToast()
+const { copy, copied } = useClipboard()
+const site = useSiteConfig()
+
+const mdPath = computed(() => `${site.url}/raw${route.path}.md`)
+
+const items = [
+  {
+    label: 'Copy Markdown link',
+    icon: 'i-lucide-link',
+    onSelect() {
+      copy(mdPath.value)
+      toast.add({
+        title: 'Copied to clipboard',
+        icon: 'i-lucide-check-circle'
+      })
+    }
+  },
+  {
+    label: 'View as Markdown',
+    icon: 'i-simple-icons:markdown',
+    target: '_blank',
+    to: `/raw${route.path}.md`
+  },
+  {
+    label: 'Open in ChatGPT',
+    icon: 'i-simple-icons:openai',
+    target: '_blank',
+    to: `https://chatgpt.com/?hints=search&q=${encodeURIComponent(`Read ${mdPath.value} so I can ask questions about it.`)}`
+  },
+  {
+    label: 'Open in Claude',
+    icon: 'i-simple-icons:anthropic',
+    target: '_blank',
+    to: `https://claude.ai/new?q=${encodeURIComponent(`Read ${mdPath.value} so I can ask questions about it.`)}`
+  }
+]
+
+async function copyPage() {
+  copy(await $fetch<string>(`/raw${route.path}.md`))
+}
+</script>
+
+<template>
+  <UButtonGroup>
+    <UButton
+      label="Copy page"
+      :icon="copied ? 'i-lucide-copy-check' : 'i-lucide-copy'"
+      color="neutral"
+      variant="outline"
+      :ui="{
+        leadingIcon: [copied ? 'text-primary' : 'text-neutral', 'size-3.5']
+      }"
+      @click="copyPage"
+    />
+    <UDropdownMenu
+      :items="items"
+      :content="{
+        align: 'end',
+        side: 'bottom',
+        sideOffset: 8
+      }"
+      :ui="{
+        content: 'w-48'
+      }"
+    >
+      <UButton
+        icon="i-lucide-chevron-down"
+        size="sm"
+        color="neutral"
+        variant="outline"
+      />
+    </UDropdownMenu>
+  </UButtonGroup>
+</template>