Remove embedded remote images from README.rst The documentation files shipped with Debian packages should not embed remote images, especially not from sources that are known to track users (like shields.io).
Remove sphinx dependency `sphinxcontrib.zopeext.autointerface` `sphinxcontrib.zopeext` is not available in Debian. We might want to package it for Debian one day, but until then let's just ignore the dependency (and make a small part of the docs not build properly).
