added links to OpenFermion/OpenFermion-Cirq (#709)
added links to OpenFermion/OpenFermion-Cirq (#709)

* added links to OpenFermion/OpenFermion-Cirq

* Update README.rst

balopat/Cirq,quantumlib/Cirq,balopat/Cirq,balopat/Cirq,quantumlib/Cirq,quantumlib/Cirq,quantumlib/Cirq,quantumlib/Cirq