Add Screenshots of API key vs No API key

Hey,

from a quick glance it is not very obvious that using an API key is optional. Maybe you want to add this information to your very first FAQ point.

It would also be a nice to have to see screenshots of both versions – with and without key – next to each other.

Sidenote: The only screenshot you have is super low resolution / unreadable.

All of this to support your plugin.