chore(CONTRIBUTORS.md): add note for new contributors (#2571)

* chore(CONTRIBUTORS.md): add note for new contributors

* review fix

* one more verbiage fix

CONTRIBUTING.md

@@ -1,5 +1,7 @@
 Esri welcomes contributions from anyone and everyone. Please see our [guidelines for contributing](https://github.com/esri/contributing).
 
+Note: New contributors should first contact [Julio Ochoa](JOchoa@esri.com) or [Juan Carlos Franco](JFranco@esri.com) to join the [Calcite Components GitHub team](https://github.com/orgs/Esri/teams/calcite-components/members). Then, clone the repo via SSH key on your machine (this Git workflow is required in order to work with our Screener test integration).
+
 ### I want to contribute, what should I work on?
 
 Calcite Components is still in its early stages. You can help most by: