docs: dev PR template comments

Updated the developer pull request template to include comments for clarity.

Author: wesleyboar

.github/PULL_REQUEST_TEMPLATE/developer.md

@@ -1,29 +1,36 @@
 ## Overview
 
-…
+<!--
+One to two sentences.
+-->
 
+<!--
 ## Related
 
-<!--
 - [DES-XYZ](https://tacc-main.atlassian.net/browse/DES-123)
 - requires _some_other_pr_
 - required by _some_other_pr_
--->
+-->…
 
 ## Changes
 
-…
+<!--
+- succinct list of changes that summarizes diff
+-->
 
 ## Testing
 
-1.
+1. 
 
 ## UI
 
-…
+<!--
+| before | after |
+| - | - |
+| … | … |
+-->
 
 <!--
 ## Notes
 
 …
--->