nothing really changed, just some updates for CRAN

This version adds convenience functions for converting list-of-lists style choice data for use with echoice2. A vignette is added demonstrating how to convert the camera dataset in 'bayesm'.

This release brings a vignette on volumetric choice modeling.
When installing from Github, remember to tell install_github to include the vingette, i.e.

remotes::install_github("ninohardt/echoice2", build_vignettes = TRUE)

Now supports when no OpenMP is available in the toolchain. Unfortunately, CRAN's MacOS servers do not have the correct toolchain, and therefore the official CRAN Mac binaries do not support multicore. I am attaching a binary version for Apple Silicon macs that I compiled on a M1 Mac running Ventura with OpenMP.

This is the initial CRAN release.

demand simulators: performance and stability improvements

Initial release of echoice2.