[master] further clarify edns doc
[master] further clarify edns doc

pecharmin/bind9,pecharmin/bind9,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,pecharmin/bind9,each/bind9-collab,each/bind9-collab,pecharmin/bind9,each/bind9-collab,each/bind9-collab