sshd_config & ….d/README: note min version & date

etc/ssh/sshd_config

@@ -1,4 +1,5 @@
-# Copied from Fedora 33
+# Copied from Fedora 33. Requires OpenSSHd 8.2 released on 2020-02-14
+#  https://www.openssh.com/txt/release-8.2
 # To modify the system-wide sshd configuration, create a  *.conf  file under
 #  /etc/ssh/sshd_config.d/  which will be automatically included below
 Include /etc/ssh/sshd_config.d/*.conf

etc/ssh/sshd_config.d/README.md

@@ -2,6 +2,9 @@ sshd_config should include something like
 
 Include /etc/ssh/sshd_config.d/*.conf
 
+NOTE: This became supported only at OpenSSHd 8.2 on 2020-02-14.
+https://www.openssh.com/txt/release-8.2
+
 ## See also
 
 https://infosec.mozilla.org/guidelines/openssh