Www.freepbx.org/configuration_files missing?

Lots of configuration files include the warning :

;--------------------------------------------------------------------------------;
; Do NOT edit this file as it is auto-generated by FreePBX. All modifications to ;
; this file must be done via the web gui. There are alternative files to make ;
; custom modifications, details at: http://freepbx.org/configuration_files ;
;--------------------------------------------------------------------------------;

But that url gives the “Oops! That page can’t be found” message.
Is this working as intended ?