use graphical plot function for Cirq

This may not be quite working yet. Cirq, like Forest, has the ability to output to a LaTeX figure. This doesn't quite work on my setup, because the output is a circuit.pdf file rather than the expected circuit.png file, but the code to produce this is the same (modulo the framework) as what's in the Forest version of the file, so presumably you've done something to configure pdflatex to output a .png rather than .pdf file.

If you have configured pdflatex to do this, can you tell me how, so I can test it on my end? And if not, maybe you can look at it and see what's missing to get it to work.

Thanks.