[doc] update a bit the documentation
Also convert the README in rst (so it can be properly displayed on
cubicweb.org).
.. _tools_module:
:mod:`pyramid_cubicweb.tools`
----------------------------
.. automodule:: pyramid_cubicweb.tools
.. autofunction:: includeme
.. autofunction:: clone_user
.. autofunction:: cnx_attach_entity
.. autofunction:: cached_build_user
.. autofunction:: clear_cache