feat: getPartFile test page

src/index.tsx

-import { useEffect } from 'react';
+import { useEffect, useState } from 'react';
 import Jensen from '..';
 import './index.css';
 
 const jensen = new Jensen();
 
 export function Home() {
+  const [files, setFiles] = useState<Jensen.FileInfo[]>([]);
+
   useEffect(() => {
     jensen.connect();
     jensen.onconnect = () => {
       console.log('connect successfully');
+      jensen.listFiles().then((res) => {
+        setFiles(res);
+      });
     };
   }, []);
 
-  return <button onClick={() => jensen.connect()}>Click to connect</button>;
+  const getFilePart = () => {
+    const file = files[4];
+    const secondsLength = Math.ceil(file.length / file.duration) * 1000;
+    console.time('!!!time');
+    jensen.getFilePart(file.name, secondsLength * 600, (res) => {
+      if (res instanceof Uint8Array) {
+        console.timeEnd('!!!time');
+      }
+    });
+  };
+
+  return (
+    <div style={{ display: 'flex', flexDirection: 'column', gap: '16px', padding: '16px', alignItems: 'center' }}>
+      <button style={{ width: '200px', height: '50px' }} onClick={() => jensen.connect()}>
+        Click to connect
+      </button>
+      <button style={{ width: '200px', height: '50px' }} onClick={getFilePart}>
+        get File Part
+      </button>
+    </div>
+  );
 }