update contributing.md

CONTRIBUTING.md

@@ -31,4 +31,8 @@ Any files generated using `tsc` will be added to `lib/*`, however those files al
 
 Tests are included under `_tests_/*` and can be run using `npm run-script test`.
 
-We ask that you include a link to a successful run that utilizes the changes you are working on. For example, if your changes are in the branch `newAwesomeFeature`, then show an example run that uses `setup-python@newAwesomeFeature` or `my-fork@newAwesomeFeature`. This will help speed up testing and help us confirm that there are no breaking changes or bugs.
+We ask that you include a link to a successful run that utilizes the changes you are working on. For example, if your changes are in the branch `newAwesomeFeature`, then show an example run that uses `setup-python@newAwesomeFeature` or `my-fork@newAwesomeFeature`. This will help speed up testing and help us confirm that there are no breaking changes or bugs.
+
+### Licensed
+
+This repository uses a tool called [Licensed](https://github.com/github/licensed) to verify third party dependencies. You may need to locally install licensed and run `licensed cache` to update the dependency cache if you install or update a production dependency. If licensed cache is unable to determine the dependency, you may need to modify the cache file yourself to put the correct license. You should still verify the dependency, licensed is a tool to help, but is not a substitute for human review of dependencies.