Fix exercise urls

Author: chriswblake

.github/steps/x-review.md

@@ -15,6 +15,6 @@ You've learned essential skills for collaborative development on GitHub:
 
 Check out other [GitHub Skills exercises](https://learn.github.com/skills).
 
-- [GitHub Pages](https://github.com/skills/github-pages) - Publish your own static website for free.
-- [Communicate using Markdown](https://github.com/skills/communicate-using-markdown) - Improve your documentation skills
+- [GitHub Pages](https://github.com/skills-dev/github-pages) - Publish your own static website for free.
+- [Communicate using Markdown](https://github.com/skills-dev/communicate-using-markdown) - Improve your documentation skills
 - [Getting Started with GitHub Copilot](https://github.com/skills/getting-started-with-github-copilot) - Learn, build, debug and ship faster with an AI pair programmer.