Synchronously get the gzipped size of a string or buffer.
@returns The gzipped size of `input`.
@example
```
import gzipSize = require('gzip-size');
const text = 'Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus.';