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
displaying line numbers for 1-line snippets is overkill
use 'versionadded' Sphinx directive
user 'deprecated' Sphinx directive
provide a link to the class; lineno for a 1-liner is overkill
replace 'note' with 'versionadded'
make path API docs a bit more concise
capitalize
avoid needless repetition

These are already stated on the function definition.
use a more correct directive
Update docs/narr/extending.rst

Fixed grammatical typo
Merge pull request #825 from calvinhp/master

Reading the docs and found a small typo