Add useChat quickstart to assistant message API page (#1738)

* fix capitalization

* add useChat example

* add messages placeholder

* fix split string

Author: ethanpalm

api/assistant/create-assistant-message.mdx

@@ -2,16 +2,65 @@
 openapi: POST /assistant/{domain}/message
 ---
 
+## Integration with `useChat`
+
+The recommended way to integrate the assistant API into your application is with the `useChat` hook from [Vercel's AI SDK](https://sdk.vercel.ai/docs).
+
+<Steps>
+<Step title="Install the AI SDK">
+
+```bash
+npm i ai
+```
+
+</Step>
+<Step title="Use the hook">
+
+```tsx
+import { useChat } from 'ai/react';
+
+function MyComponent({ domain }) {
+  const { messages, input, handleInputChange, handleSubmit, isLoading } = useChat({
+    api: `https://api-dsc.mintlify.com/v1/assistant/${domain}/message`,
+    headers: {
+      'Authorization': `Bearer ${process.env.MINTLIFY_TOKEN}`,
+    },
+    body: {
+      fp: 'anonymous',
+      messages: [
+        { role: 'user', content: 'What is this documentation about?' }
+      ]
+    },
+    streamProtocol: 'data',
+    sendExtraMessageFields: true,
+  });
+
+  return (
+    <div>
+      {messages.map((message) => (
+        <div key={message.id}>
+          {message.role === 'user' ? 'User: ' : 'Assistant: '}
+          {message.content}
+        </div>
+      ))}
+      <form onSubmit={handleSubmit}>
+        <input value={input} onChange={handleInputChange} />
+        <button type="submit">Send</button>
+      </form>
+    </div>
+  );
+}
+```
+
+</Step>
+</Steps>
+
+See [useChat](https://ai-sdk.dev/docs/reference/ai-sdk-ui/use-chat) in the AI SDK documentation for more details.
+
 ## Rate limits
 
 The assistant API has the following limits:
 
 - 10,000 uses per key per month
 - 10,000 requests per Mintlify organization per hour
-- 10,000 requests per IP per day
-
-## Suggested usage
-
-For best results, use the [useChat hook from ai-sdk](https://ai-sdk.dev/docs/reference/ai-sdk-ui/use-chat#usechat) to send requests and handle responses.
-
-You can set `fp`, `threadId`, and `filter` in the `body` field of the options parameter passed to the hook.
+- 10,000 requests per IP per day

docs.json

@@ -275,7 +275,7 @@
             ]
           },
           {
-            "tab": "API Reference",
+            "tab": "API reference",
             "groups": [
               {
                 "group": "API reference",