Fix link to open source license in CONTRIBUTING.md

Updated the link to the project's open source license in the CONTRIBUTING.md file.

Author: salvador-barboza

CONTRIBUTING.md

@@ -6,7 +6,7 @@
 
 Hi there! We're thrilled that you'd like to contribute to this project. Your help is essential for keeping it great.
 
-Contributions to this project are [released](https://help.github.com/articles/github-terms-of-service/#6-contributions-under-repository-license) to the public under the [project's open source license](LICENSE.txt).
+Contributions to this project are [released](https://help.github.com/articles/github-terms-of-service/#6-contributions-under-repository-license) to the public under the [project's open source license](LICENSE).
 
 Please note that this project is released with a [Contributor Code of Conduct](CODE_OF_CONDUCT.md). By participating in this project you agree to abide by its terms.
 
@@ -39,4 +39,4 @@ Here are a few things you can do that will increase the likelihood of your pull
 
 - [How to Contribute to Open Source](https://opensource.guide/how-to-contribute/)
 - [Using Pull Requests](https://help.github.com/articles/about-pull-requests/)
-- [GitHub Help](https://help.github.com)
+- [GitHub Help](https://help.github.com)