Update pr template (#745)

* docs: update pr template

* docs: update further

* docs: update pr template further

Author: scaliby

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,9 +1,18 @@
-## Fixes / Features
--
--
+# Description
+<!--
+Describe your change. 
+What does it introduce?
+Why do we need it?
+If you are releasing a feature, have you updated documentation?
+-->
 
-## Testing / Documentation
-Testing details.
+# Issue
+<!--
+Is there any related issue this change is trying to fix?
+-->
 
-- [ y/n ] Tests pass
-- [ y/n ] Appropriate changes to documentation are included in the PR
+# Testing
+<!--
+Have you performed any manual testing on your change?
+Have you verified use cases affected by goldens?
+-->