Updated the README.rst
Updated the README.rst

Updated the Readme.rst with some formatting issues. Also
stole the ending line from the Nova to point in the direction
of the CONTRIBUTING.rst.

Change-Id: I595b7feb641aee91d47ba55eedab29e7511bfa35

CiscoSystems/networking-odl,FedericoRessi/networking-odl,schoksey/networking-odl,schoksey/networking-odl,flavio-fernandes/networking-odl,mestery/x-stackforge-odl,openstack/networking-odl,CiscoSystems/networking-odl,FedericoRessi/networking-odl,openstack/networking-odl,flavio-fernandes/networking-odl,openstack/networking-odl