Create pull_request_template.md

Using the same pull request template as what we have in FreeRTOS/FreeRTOS.

.github/pull_request_template.md

@@ -0,0 +1,16 @@
+<!--- Title -->
+
+Description
+-----------
+<!--- Describe your changes in detail. -->
+
+Test Steps
+-----------
+<!-- Describe the steps to reproduce. -->
+
+Related Issue
+-----------
+<!-- If any, please provide issue ID. -->
+
+
+By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.