Merge pull request NCAR#188 from NCAR/PR-template-patch

Update PULL_REQUEST_TEMPLATE.md

Author: TeaganKing

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,7 +2,7 @@
 * [ ] Please add an explanation of what your changes do and why you'd like us to include them.
 
 #### All PRs Checklist:
-* [ ] Have you followed the guidelines in our [Contributor's Guide](https://ncar.github.io/CUPiD/ContributorGuide.html)?
+* [ ] Have you followed the guidelines in our [Contributor's Guide](https://ncar.github.io/CUPiD/contributors_guide.html)?
 * [ ] Have you checked to ensure there aren't other open [Pull Requests](../../../pulls) for the same update/change?
 * [ ] Have you made sure that the [`pre-commit` checks passed (#8 in Adding Notebooks Guide)](https://ncar.github.io/CUPiD/addingnotebookstocollection.html)?
 * [ ] Have you successfully tested your changes locally?