Add pull request template

.github/pull_request_template.md

@@ -0,0 +1,10 @@
+## Description
+<!-- Describe your changes in detail -->
+
+## Checklist before requesting a review
+- [ ] I have performed a self-review of my code
+- [ ] I have tested my changes
+- [ ] I have added unit tests that prove my changes work
+
+## Screenshots (if appropriate)
+<!-- Relevant screenshots of the game client helps everyone understand the changes better -->