Update contributing.md

contributing.md

@@ -4,7 +4,7 @@ Please note that this project is released with a [Contributor Code of Conduct](c
 ## Adding courses/certificates
 To ensure this project keeps growing, we rely on community contributions. 
 
-If you'd like to add a free course with a certificate/badge to [awesome-certificates](readme.md):
+If you'd like to add a free course with a certificate/badge to [awesome-certificates](README.md):
 - **First:** [fork this project](https://github.com/PanXProject/awesome-certificates/fork) and make the edits you need. 
 - **Second:** open a [pull request](https://github.com/PanXProject/awesome-certificates/compare), if you're new to pull requests read about it [here](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request).
 - **Third:** read and adhere to the [list guidelines](pull_request_template.md).