Added phpdoc_separation fixer

The idea here is to go from:

```php
    /**
     * @param EngineInterface $templating
     * @return void
     */
```

to 

```php
    /**
     * @param EngineInterface $templating
     *
     * @return void
     */
```
So how do I explode these then?

```php
$lines = explode("\n", $content);
```

^^^ That doesn't cut it. :(