ci: Extended pull request template (#423)

* ci: Extended pull request template

* ci: slight realigment of sections

.github/pull_request_template.md

@@ -1,10 +1,16 @@
 ## Issue addressed
 Solves #<issue number>
 
+## Code of conduct
+- [ ] I HAVE NOT added sensitive or compromised (test) data to the repository.
+- [ ] I HAVE NOT added vulnerabilities to the repository.
+- [ ] I HAVE discussed my solution with (other) members of the RA2CE team.
+
 ## What has been done?
 Explain how you addressed the resolution of the related issue, what choices you made and why.
 
-## Checklist
+### Checklist
+- [ ] Code is formatted using our custom `black` and `isort` definitions.
 - [ ] Tests are either added or updated.
 - [ ] Branch is up to date with `master`.
 - [ ] Updated documentation if needed.