Update CONTRIBUTING.md

Author: Adam Dupaski

CONTRIBUTING.md

@@ -1,4 +1,4 @@
 For guidelines on contributing to the Mendix documentation, please see these two documents:
 
-* [How to Contribute to the Mendix Documentation](https://docs.mendix.com/developerportal/community-tools/contribute-to-mendix-docs)
-* [Documentation Writing Guidelines](https://docs.mendix.com/developerportal/community-tools/documentation-guidelines)
+* [How to Contribute to Mendix Docs](https://docs.mendix.com/community-tools/contribute-to-mendix-docs/)
+* [Documentation Writing Guidelines](https://docs.mendix.com/community-tools/documentation-guidelines/)