bookwyrm socail icon

[Kuchenmampfer]

Hi,
I want to have a bookwyrm social icon, but don't understand how to add it myself.
I have found the png at https://bookwyrm-social.sfo3.digitaloceanspaces.com/images/logos/886fa857d5f6b7e9.png
So it would be great if either someone could add it or gave me instructions on how to add and use it myself.
In case you decide to give me instructions, I would be happy to write them into the docs and make a PR so others can more easily understand this as well :)