[tox] Simplify command line to build the doc

[pyramid] Drop warning about pyramid_debugtoolbar not found in debug mode Some people way want to run a pyramid server in debug mode without the toolbar. This warning is annoying for them. Others should just install and *include* the toolbar by hand.

[pkg] Add development.ini.tmpl to "cubicweb.pyramid" package data Otherwise the file is not installed and `cubicweb-ctl create -c pyramid` does not work.

[skeleton] Don't use system site packages in tox environment As we changed this in cubicweb, there is a consensus that this is not the best practice so let us change it as well for skeleton.

[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.

[doc] Update the "quickstart" page of pyramid documentation Again mentioning the two modes of operations and dropping references to prior implementation.

[doc] Rewrite "pyramid" index page in the book We drop references to pyramid-cubicweb and cubicweb-pyramid, remaining of the merge in 3.24. We now mention the two possible operation modes (with bwcompat being true or false).

[doc] Drop documentation for cubicweb.pyramid.tools module Which, as documented, mostly consists of internals.

[doc] Drop reference to "make_cubicweb_application" in pyramid doc This function got renamed into config_from_cwconfig and this is arguably an internal detail so should not appear in the API documentation.

[doc] Remove trailing whitespaces in doc/book/pyramid/index.rst