chore: tweak wording in issue template

Author: jelbourn

.github/ISSUE_TEMPLATE.md

@@ -16,7 +16,7 @@ Plunker template: http://plnkr.co/edit/o077B6uEiiIgkC0S06dd
 #### What is the use-case or motivation for changing an existing behavior?
 
 
-#### What are the relevant versions of Angular, Material, OS, affected browsers, etc.?
+#### Which versions of Angular, Material, OS, browsers are affected?
 
 
 #### Is there anything else we should know?