docs: correct license reference in contrib docs

Author: erikgb

CONTRIBUTING.md

@@ -1,7 +1,7 @@
 # Contributing
 
-Weave Gitops is a [Mozilla Public License(MPL2)](LICENSE) project. This is a Weaveworks
-open source product with a community led by Weaveworks :heart:
+Weave Gitops is a [Apache-2.0](LICENSE) project. This is an open source product with a community
+led by volunteers interested in the brilliant software originally created by Weaveworks. :heart:
 
 We welcome improvements to reporting issues and documentation as well as to code.