Add custom images to footer

[Loukitos]

I want to make the payment methods in footer customizable by the Theme Edit Tool. 

How can I add custom fields in this inline list?  

<ul class="inline-list payment-icons">
          {% for type in shop.enabled_payment_types %}
            <li>
              {{ type | payment_type_svg_tag: class: 'icon' }}
            </li>
            <li>
              test
            </li>
          {% endfor %}
        </ul>

 
I know that I can insert the image in the list but I want to change the logos from the theme editor with custom parameters. Is it possible?