[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.

version=3
opts=uversionmangle=s/(rc|a|b|c)/~$1/ \
https://pypi.debian.net/cubicweb/cubicweb-(.+)\.(?:zip|tgz|tbz|txz|(?:tar\.(?:gz|bz2|xz)))