There wasn't, but there is now ;-) Check out the latest commit on github/master, build/install, and you will have a
cadabra2latex command, which does
cadabra2latex in.cnb out.tex
This will create
out.tex from your notebook
in.cnb, plus any
outnnn.png files if your notebook contains plots. You should then be able to do e.g.
to build a PDF.