build: add pull request template

Author: kacperzolkiewski

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,21 @@
+<!-- Thanks for submitting a pull request! We appreciate you spending the time to work on these changes. Please follow the template so that the reviewers can easily understand what the code changes affect -->
+
+# Summary
+
+Explain the **motivation** for making this change: here are some points to help you:
+
+- What issues does the pull request solve? Please tag them so that they will get automatically closed once the PR is merged
+- What is the feature? (if applicable)
+- How did you implement the solution?
+- What areas of the library does it impact?
+
+## Test Plan
+
+Demonstrate the code is solid. Example: The exact commands you ran and their output, screenshots / videos if the pull request changes UI.
+
+## Compatibility
+
+| OS      | Implemented |
+| ------- | :---------: |
+| iOS     |    ✅❌     |
+| Android |    ✅❌     |