Update to README.rst
Update to README.rst

This update finally catches up the reStructuredText version of this
README with the markdown version.

crunchr/silk,crunchr/silk,django-silk/silk,django-silk/silk,mtford90/silk,crunchr/silk,crunchr/silk,mtford90/silk,django-silk/silk,jazzband/silk,jazzband/silk,mtford90/silk,mtford90/silk,django-silk/silk,jazzband/silk,jazzband/silk