Fixing the typo is pretty self explanatory, but the Cloudflare Workers doc change needs a little more explanation:

Unfortunately, Cloudflare Workers does not expose the ReadableStream constructor, which means it's not as simple as return new Response(renderToWebStream(app)) here.

There are ways to get this to work in Cloudflare Workers via ponyfill-ing ReadableStream, and then manually writing back to a TransformStream which is available in their environment, and ends up looking something like this:

...
import {ReadableStream as polyReadableStream} from 'web-streams-polyfill/dist/ponyfill.es2018.mjs';

async function pipeReaderToWriter(reader, writer){
	const encoder = new TextEncoder();
	for(;;){
		const {value, done} = await reader.read();
		const encoded = encoder.encode(value);
		await writer.write(encoded);
		if(done){
			break;
		}
	}
	writer.close();
}
...

...
const {readable, writable} = new TransformStream();
const render = renderToWebStream(app, {}, polyReadableStream);
pipeReaderToWriter(render.getReader(), writable.getWriter());
return new Response(readable);
...

More discussion can be found in #4243.

I figured that this complexity is very Cloudflare Workers specific, so perhaps wouldn't make sense to include in the README here. However I think it's a good idea to remove the CF Workers reference here, so others aren't confused about this not working in future. If it makes sense, I'd be happy to contribute some docs somewhere (where?) about this, or extend this README if you feel it makes the most sense here. Let me know.