Ask HN: How to open source the code but not the branding?

I have a website that I am building for a "personal side project that may someday make money". I have the code for the website on Github, because right now there isn't that anything groundbreaking or new about the website code.

I want to license it to be as permissible as possible (I usually do MIT), but I do not want to somehow give away the "branding" of the name. I own the domain name.

How do I license the site code as "free to use and change for your own use as long as you don't attempt to impersonate the original owner"?