chore: added pull request template

Author: Marshevskyy

.github/pull_request_template.md

@@ -0,0 +1,18 @@
+## What/Why/How?
+
+## Reference
+
+## Testing
+
+## Screenshots (optional)
+
+## Check yourself
+
+- [ ] Code is linted
+- [ ] Tested
+- [ ] All new/updated code is covered with tests
+
+## Security
+
+- [ ] Security impact of change has been considered
+- [ ] Code follows company security practices and guidelines