chore: add pull request template

Signed-off-by: Thomas Schuetz <thomas.schuetz@t-sc.eu>

.github/pull_request_template.md

@@ -0,0 +1,21 @@
+<!-- 
+Thanks for creating this pull request 🤗
+
+Please make sure that the pull request is limited to one type (docs, feature, etc.) and keep it as small as possible. You can open multiple prs instead of opening a huge one.
+-->
+
+<!-- If this pull request closes an issue, please mention the issue number below -->
+Closes # <!-- Issue # here -->
+
+## 📑 Description
+<!-- Add a brief description of the pr -->
+
+## ✅ Checks
+<!-- Make sure your pr passes the CI checks and do check the following fields as needed - -->
+- [ ] My pull request adheres to the code style of this project
+- [ ] My code requires changes to the documentation
+- [ ] I have updated the documentation as required
+- [ ] All the tests have passed
+
+## ℹ Additional Information
+<!-- Any additional information like breaking changes, dependencies added, screenshots, comparisons between new and old behavior, etc. -->