Update .github/PULL_REQUEST_TEMPLATE/pull_request_template.md

Co-authored-by: Alex Vanyo <vanyo@google.com>

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md

@@ -6,7 +6,7 @@ label: 'triage me'
 Thank you for opening a Pull Request!
 Before submitting your PR, there are a few things you can do to make sure it goes smoothly:
 - [ ] Make sure to open a GitHub issue as a bug/feature request before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
-- [ ] Ensure the tests and linter pass
+- [ ] Ensure the tests and linter pass (`./gradlew spotlessApply` to automatically apply formatting)
 - [ ] Appropriate docs were updated (if necessary)
 
 Is this your first Pull Request?