Every now and then (daily) I end up at some project page at GitHub, and almost always I click the “Wiki” link to read up on the project, just to get a sense about what it does and if it can help me. I’ve stopped counted the number of times I end up visiting a blank wiki or not getting to a wiki at all. And often there’s also no links on the landing page and sometimes there are links to an old blog. My immediate reaction is:
This is not a serious project.
I don’t expect you to have an external site or be using GitHub pages, but I do expect you to either use the wiki or remove it. It’s to easy to turn off for you to ignore it.