docs(examples): respond with "Hello, world!" (#99)

<!--
This pull request template provides suggested sections for framing your
work.
You're welcome to change or remove headers if it doesn't fit your use
case. :)
-->

### What are you trying to accomplish?

This PR updates the example message we write back to the client with
"Hello, world!" rather than a variant of my name. 😉

### What approach did you choose and why?

One-liner change: targeted the text and updated it to match the file's
intent.

### What should reviewers focus on?

Nothing I haven't mentioned 😉

Author: francisfuzz

examples/hello-world/index.js

@@ -12,7 +12,7 @@ const server = createServer((request, response) => {
     return response.end("ok");
   }
 
-  response.write(createTextEvent("Hello, Francis Fuzz!"));
+  response.write(createTextEvent("Hello, world!"));
   response.end(createDoneEvent());
 });