Adding Sphinx-generated documentation (refs #9502)

* adding documentation folder; contents are generated by the eea.github.com package
* registering ./documentation resourceDirectory as <package.name>.documentation
Updating documentation to define 'here'
* Change: load plone.reload meta zcml in order to avoid failing tests [ichim-david refs #18064]
* Bug fix: removed wrongly added blockquotes within README.rst [ichim-david refs #18064]
Refs #18064; resourceDirectory comes from zope.browserresource not from plone.resource