Fixed result line and added package docstring

While trimming `<p>` tags from the result line, 5 characters have been removed.
Since the markdown processor converts `"=>"` to `"=&gt;"`, the result was `"gt; ..."`.
Now everything is removed but the `<div>` for the result line is only created for existing lines,
so the `"=>"` (or some other marker like ⇒) can be added with the following css:

```css
.apiref-result {
  content: "=> ";
}
```

Additionaly, package docstrings are added to the package reference.