How can I add favicon asset?

(Using v13.2.5)

I'd like to set the favicon on my documentation. I see that I can do this with `--favicon myFavIcon.png` since https://github.com/documentationjs/documentation/pull/1207/commits/5b66910782e83eee4f9e8aa1d0528c681eba5d06
This does add the reference into index.html. But, I don't see how to add the favicon file itself into the generated assets. So, no favicon is found at runtime.
How do I add the icon? Am I just missing something obvious?