Create simple web-app that creates GitHub author by username

In open-source it's sometimes great to add someone else as author to a commit.
As it's nearly impossible to get the real email by the other user we can use the GitHub generated email address.
This email address isn't public - but it follows always the same structure.
Using the GitHub API we can create this by the username.

Somewhen back I've created a simple node.js CLI file that does the job.
But a simple web app that has an input and generates the same output would be great.

```js
const fetch = require('node-fetch');

const username = process.argv.slice(-1).pop();

fetch(`https://api.github.com/users/${username}`, {
method: 'GET',
headers: {
'user-agent': 'GitHub-Author-Generator',
}
})
.then(res => res.json())
.then(json => `${json.name} <${json.id}+${json.login}@users.noreply.github.com>`)
.then(console.log);
```

This script doesn't require any access token - so it should be possible to do the call in the users browser, so we can host it statically without any backend.