Show description summary instead of bulleted details

When there is no description available, we'll show some placeholder text.
If you're passing `"somewhere"` for both calls of `set_description_id_to`, is it necessary to have the argument? It could probably just be moved to the method, since it's not being used in the tests either.

```ruby
def set_description_id
  stub_const("Event::DESCRIPTION_ELEMENT_ID", "somewhere")
end
```