Recursive installation of the module

The module installs itself in the example folder. This leads to a weird recursive installation chain with going back to older versions.

```
node_modules/pdf-creator-node@2.3.5
  |_ examples/pdf-creator-node@2.3.4
     |_ examples/pdf-creator-node@2.2.4
       |_ examples/pdf-creator-node@1.4.3
```

The example folder should not be included in the npm module.