Update PULL_REQUEST_TEMPLATE.md

Author: fdiblen

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,8 +1,15 @@
 # Pull request details
 
+As a contributor I confirm,
+- [ ] I read and followed the instructions in [CONTRIBUTING.md](CONTRIBUTING.md)
+- [ ] The developer documentation is up to date with the changes introduced in this Pull Request
+- [ ] Tests are passing
+- [ ] All the workflows are passing
+
 ## List of related issues or pull requests
 
-Refs: #ISSUE_NUMBER
+Refs: 
+- #ISSUE_NUMBER
 
 
 ## Describe the changes made in this pull request