@Template annotation doesn't recognize non-html templates

Code example:

```
    /**
     * @Route("/some/info", name="route_name", defaults={"_format"="json"})
     * @Method({"GET"})
     *
     * @Template()
     */
    public function someAction()
    {
            ...
    }
```

In this case, the `@Template` annotation isn't clickable, because it expects a `.html.twig` file, instead of the `.json.twig` that I'm using.

Can we fix this, please?
