Wasmtime tutorial is incorrect: Import #0 module="wasi_snapshot_preview1" error: module is not an object or function

After following the wasmtime tutorial https://github.com/bytecodealliance/wasmtime/blob/main/docs/WASI-tutorial.md I am unable to run the resulting output in the polyfill site.

The site errors with `Import #0 module="wasi_snapshot_preview1" error: module is not an object or function`

I have compiled the rust example in the tutorial, and even dumbed it down slighty so that it doesnt require CLI arguments. Here is my code.

```rust
use std::fs;
use std::io::{Write, self};

fn process(input_str: &str, output_fname: &str) -> Result<(), String> {

let mut output_file = fs::File::create(output_fname)
.map_err(|err| format!("error opening output {}: {}", output_fname, err))?;
output_file
.write_all(input_str.as_bytes())
.map_err(|err| format!("write error: {}", err))
}

fn main() -> io::Result<()> {
if let Err(err) = process(&"Hello World", &"tmp/file.txt") {
eprintln!("{}", err)
}

io::stdout().write_all(b"done writing")?;
Ok(())
}

```

I have confirmed that this code runs as expected in the wasmtime cli