docs: PR template CHanges section shoudl have sampel bullet

Updated comment syntax for changes section in PR template.

Author: wesleyboar

.github/PULL_REQUEST_TEMPLATE/developer.md

@@ -14,9 +14,9 @@ One to two sentences.
 
 ## Changes
 
-<!--
-- succinct list of changes that summarizes diff
--->
+<!-- succinct list of changes that summarizes diff -->
+
+- …
 
 ## Testing