Enhanced doc event notification emails with who and when. Fixes issue ietf-tools#2428.

 - Legacy-Id: 14448

Author: levkowetz

ietf/templates/community/notification_email.txt

@@ -6,7 +6,8 @@ This is a notification from the {{ clist.long_name }}.
 Document: {{ event.doc }},
 https://datatracker.ietf.org/doc/{{ event.doc_id }}/
 
-Change:
+Change by {{ event.by }} on {{ event.time }}:
+
 {{ event.desc|textify|striptags }}
 
 Best regards,