feat: add PR template (#17)

Author: the-technat

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,13 @@
+## Description
+<!--- Describe your changes in detail -->
+
+## Motivation and Context
+<!--- Why is this change required? What problem does it solve? -->
+<!--- If it fixes an open issue, please link to the issue here. -->
+
+## Breaking Changes
+<!-- Does this break backwards compatibility with the current major version? -->
+<!-- If so, please provide an explanation why it is necessary. -->
+
+## How Has This Been Tested?
+- [ ] I have tested and validated these changes using an example rule