Fix style guide link.

CONTRIBUTING.md

@@ -46,7 +46,7 @@ or a factual error.
     with the top level document called `_index.md` within each subdirectory.
 
 Note: please do not submit modifications to theme or CSS items, `_header` or `_footer` files unless they 
-adhere to [UNL style guidelines](https://docs.gitlab.com/ee/user/project/issues/managing_issues.html).
+adhere to [UNL style guidelines](https://wdn.unl.edu/unl-web-framework-5-standards-guide).
 
 ## What to Contribute