update style guide reference (#1942)

Author: programming-with-ia

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing to Clerk's documentation
 
-Thanks for being willing to contribute to [Clerk's documentation](https://clerk.com/docs)! This document outlines how to effectively contribute to the documentation content located in this repository. See the [style guide](./styleguides/styleguide.md) for more information on our guidelines for writing content.
+Thanks for being willing to contribute to [Clerk's documentation](https://clerk.com/docs)! This document outlines how to effectively contribute to the documentation content located in this repository. See the [style guide](./styleguides/STYLEGUIDE.md) for more information on our guidelines for writing content.
 
 ## Written in MDX