Function watchRegistry

watchRegistry(hive: number, key: string, callback: () => void): RegWatch
Watch a registry key for any value changes. The callback is invoked on the JS event loop whenever the key or its values change. Call .close() on the returned handle to stop watching.

Watching is recursive (subkeys included).
Parameters
- hive: number
- key: string
- callback: () => void
Returns RegWatch
Example: Watch proxy settings
```
const watcher = watchRegistry(HKCU,
    'Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings',
    () => { console.log('Proxy settings changed'); });

// later…
watcher.close();
```