Update PR template

Author: joepio

pull_request_template.md

@@ -1,6 +1,7 @@
 PR Checklist:
 
-- [ ] Link to related issues:
+- [ ] Link to related issues: #number
 - [ ] Add changelog entry linking to issue
 - [ ] Add tests (if needed)
-- [ ] (If new feature) added in description / readme
+- [ ] If dependent on server-side changes: link to PR on `atomic-data-rust`
+- [ ] If new feature: added in description / readme