[Bug]: Example Code Error For File Server Hosting

### Problem description

I was trying to run a file server using deno and used this website for help: https://docs.deno.com/runtime/tutorials/file_server/#:~:text=The%20Deno%20standard%20library%20provides,%2Fbin%2Ffile%2Dserver%20.

The example(file_server.ts) uses does not run properly and ``error: Uncaught SyntaxError: Unexpected reserved word
const file = await Deno.open("." + filepath, { read: true });`` is logged in terminal

### Steps to reproduce

1. Go onto https://docs.deno.com/runtime/tutorials/file_server/#:~:text=The%20Deno%20standard%20library%20provides,%2Fbin%2Ffile%2Dserver%20.
2. Copy and paste the example code from file_server.ts
```Deno.serve(
{ hostname: "localhost", port: 8080 },
(request) => {
// Use the request pathname as filepath
const url = new URL(request.url);
const filepath = decodeURIComponent(url.pathname);

// Try opening the file
try {
const file = await Deno.open("." + filepath, { read: true });

// Stream the file as it's read to the response. That way we don't
// need to load the full file into memory.
return new Response(file.readable);
} catch {
// If the file cannot be opened, return a "404 Not Found" response
return new Response("404 Not Found", { status: 404 });
}
},
);
```
3. Use ``deno run --allow-read=. --allow-net file_server.ts`` in terminal

### Expected behavior

It should run and I should be able to open a browser on localhost

### Environment

-Deno Version: 1.44.1
-OS:
Edition: Windows 11 Home
Version: 23H2
Installed on: ‎2023-‎03-‎31
OS build: 22631.4169
Experience: Windows Feature Experience Pack 1000.22700.1034.0

### Possible solution

replace code with
```
Deno.serve(
{ hostname: "localhost", port: 8080 },
async (request) => {
// Use the request pathname as filepath
const url = new URL(request.url);
const filepath = decodeURIComponent(url.pathname);

// Try opening the file
try {
const file = await Deno.open("." + filepath, { read: true });

// Stream the file as it's read to the response. That way we don't
// need to load the full file into memory.
return new Response(file.readable);
} catch {
// If the file cannot be opened, return a "404 Not Found" response
return new Response("404 Not Found", { status: 404 });
}
},
);
```

### Additional context

_No response_