[doc] Update "settings" pyramid documentation Document that without "bwcompat" we can use a development.ini file directly and add a dedicated section to list configuration options.

etc/init.d
etc/cubicweb.d
etc/bash_completion.d
usr/bin
usr/share/doc/cubicweb-ctl
var/log/cubicweb
var/lib/cubicweb/backup
var/lib/cubicweb/instances