fix link in CONTRIBUTING.md to LICENSE.txt

Author: spier

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 The goal of the InnerSource patterns working group is to collect, document, and publish InnerSource best practices. To make the best practices easy to comprehend, evaluate, and apply, we codify them in a specific structure - [the patterns format](meta/pattern-template.md). More infos on the working group can be found in our [README.md](README.md) file.
 
-For this working group to strive, we welcome your contribution - be it small or huge. 
+For this working group to strive, we welcome your contribution - be it small or huge.
 
 
 ## How to Contribute?
@@ -31,7 +31,7 @@ We are happy to support you in contributing to the InnerSource patterns or to ju
 
 ## License of Contributions
 
-The contents of this repository are licensed under [CC-BY-SA-4.0](LICENSE.md). By contributing to this repository, you grant us (and everyone else for that matter) the right to use your contribution in accordance with that license.
+The contents of this repository are licensed under [CC-BY-SA-4.0](LICENSE.txt). By contributing to this repository, you grant us (and everyone else for that matter) the right to use your contribution in accordance with that license.
 
 
 ## Code of Conduct