docs(github): add PULL_REQUEST_TEMPLATE.md

Author: remarkablemark

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,29 @@
+<!-- Filling out the information below can facilitate the review/merge of the PR. -->
+
+### What is the motivation for this pull request?
+
+<!-- Is this a feature, bug fix, docs, etc.? -->
+
+### What is the current behavior?
+
+<!-- Please link to the issue (if applicable). -->
+
+### What is the new behavior?
+
+<!-- If this is a feature change or bug fix. -->
+
+### Checklist:
+
+<!--
+Feel free to remove any item that is irrelevant to your changes.
+To check an item, place an "x" in the box like so:
+- [x] Tests
+-->
+
+- [ ] Tests
+- [ ] Documentation
+
+<!--
+Do you have any additional comments?
+Thanks for contributing!
+-->