Requiring jsoneditor instead of manual import

I believe it would be a lot easier if you used in the component:
```typescript
import { JSONEditor } from 'jsoneditor';
```
and also users could get the styles from
```scss
@import "~jsoneditor/dist/jsoneditor.min.css";
```
This would work by adding `jsoneditor` as a dependency. Including the libraries from the CDN is not really the angular/npm way