Add PR template (#274)

## Changes
<!-- Summary of your changes that are easy to understand -->
Add PR template to bring structure to PRs. 

## Tests
<!-- How is this tested? -->
Copy pasted template in this description to check how it looks.
Template working in VSCode repository

## Public Tickets
<!--
Link to public tickets (if any). Please don't mention internal tickets.
-->
N/A

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,6 @@
+## Changes
+<!-- Summary of your changes that are easy to understand -->
+
+## Tests
+<!-- How is this tested? -->
+