Fix tutorials/state_histograms.ipynb as part of docs cleanup for Cirq 1.0 (#5206)
Fix tutorials/state_histograms.ipynb as part of docs cleanup for Cirq 1.0 (#5206)

* Cleared output
* Fixed broken links
* Minor improvements in content
quantumlib/Cirq,quantumlib/Cirq,quantumlib/Cirq,quantumlib/Cirq,quantumlib/Cirq