rm redundant info; this is just a repeat of what is already displayed
use simpler language
a more accurate note
consistency fix
add missing comma
formatting fix
remove extraneous 'a'
pyramid.config: take advantage of some Sphinx directives

* versionadded
* versionchanged
* deprecated
improve paragraph

inspired by https://github.com/Pylons/pyramid/pull/815#discussion_r2737923
Merge pull request #815 from tshepang/temp

some pyramid.config API documentation improvements