Add contributor's guide link

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md

@@ -1,6 +1,6 @@
 ### All Submissions:
 
-* [ ] Have you followed the guidelines in our Contributing document (including the `pre-commit` check)?
+* [ ] Have you followed the guidelines in our Contributer's Guide](https://github.com/NCAR/CUPiD/wiki/Contributor's-Guide) (including the `pre-commit` check)?
 * [ ] Have you checked to ensure there aren't other open [Pull Requests](../../../pulls) for the same update/change?
 
 <!-- You can erase any parts of this template not applicable to your Pull Request. -->