Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -4,8 +4,19 @@ Contributions to GMNS are governed by the [GMNS Governance Document](https://doc
 ## Opening an Issue
 If you have a question, comment, or suggestion about GMNS, you can [open an issue](https://github.com/zephyr-data-specs/GMNS/issues/new). 
 
-## Creating a Pull Request
-If you have suggested edits to the specification, or would like to contribute validation or conversion code, you can submit your proposed changes through a Pull Request. To do this, you can fork this repository, make your proposed changes on your local copy, and then submit a pull request [here](https://github.com/zephyr-data-specs/GMNS/compare).
+## Proposing Edits to this Repository
+This repository hosts the specification itself, as well as some small demo examples and tools demonstrating how the spec works.
+At this time, code or datasets (aside from the simple examples that already appear) should not be included in this repository; developers should instead create their own repositories for their work. If you're using GMNS, please let us know by submitting a pull request to the "Known Packages Using GMNS" section of this file below.
+
+## Submitting a Pull Request
+If you have suggested edits to the specification, you can submit your proposed changes through a Pull Request. To do this, you can fork this repository, make your proposed changes on your local copy, and then submit a pull request [here](https://github.com/zephyr-data-specs/GMNS/compare).
 
 ## Review Process
 Once work on a pull request is complete, the GMNS Project Management Committee will review the request. Discussion may occur via commenting on the PR, or for more substantive changes, a meeting of the PMC may be called. After discussion, the PMC Chair will call a vote of PMC members using the procedures outlined in the Governance Document.
+
+## Known Packages Using GMNS
+- [GMNSpy](https://github.com/e-lo/gmnspy) by Elizabeth Sall (@e-lo)
+- Several tools by Simon Zhou (@xzhou99) and his lab (@asu-trans-ai-lab), including:
+	- [Ocean](https://github.com/asu-trans-ai-lab/Ocean)
+	- [NeXTA-GMNS](https://github.com/asu-trans-ai-lab/NeXTA-GMNS)
+	- [OSM2GMNS](https://github.com/asu-trans-ai-lab/OSM2GMNS)