Clarified when triagers should close tickets as needsinfo.

https://groups.google.com/d/msg/django-developers/dyldP9kFADc/rHTlRBVEP8MJ

docs/internals/contributing/triaging-tickets.txt

@@ -349,8 +349,9 @@ Then, you can help out by:
 
 * Closing "Unreviewed" tickets as "invalid", "worksforme" or "duplicate."
 
-* Closing "Unreviewed" tickets as "needsinfo" when they're feature requests
-  requiring a discussion on `django-developers`_.
+* Closing "Unreviewed" tickets as "needsinfo" when the description is too
+  sparse to be actionnable, or when they're feature requests requiring a
+  discussion on `django-developers`_.
 
 * Correcting the "Needs tests", "Needs documentation", or "Has patch"
   flags for tickets where they are incorrectly set.