How do I create a link from a README.md file to a Wiki page in github? Every example seems to show linking from one wiki page to another wiki page, or from one README file to another file in the repository. But none that show linking from one to the other
You would have to use an absolute URL as opposed to a relative one.
For example:
[Sites Using React](https://github.com/facebook/react/wiki/Sites-Using-React)