events: Add block comment documenting naming conventions.
events: Add block comment documenting naming conventions.

Fixes part of #14166.

eeshangarg/zulip,zulip/zulip,zulip/zulip,hackerkid/zulip,zulip/zulip,rht/zulip,eeshangarg/zulip,punchagan/zulip,eeshangarg/zulip,hackerkid/zulip,kou/zulip,zulip/zulip,eeshangarg/zulip,andersk/zulip,kou/zulip,punchagan/zulip,andersk/zulip,andersk/zulip,andersk/zulip,kou/zulip,hackerkid/zulip,eeshangarg/zulip,rht/zulip,punchagan/zulip,andersk/zulip,punchagan/zulip,punchagan/zulip,rht/zulip,punchagan/zulip,punchagan/zulip,kou/zulip,rht/zulip,zulip/zulip,hackerkid/zulip,andersk/zulip,zulip/zulip,hackerkid/zulip,kou/zulip,eeshangarg/zulip,hackerkid/zulip,eeshangarg/zulip,rht/zulip,hackerkid/zulip,andersk/zulip,kou/zulip,rht/zulip,kou/zulip,zulip/zulip,rht/zulip