Make vignette data easily available

[thebioengineer]

trafficstars

https://github.com/atorus-research/Tplyr/blob/dabbcbff6c09d455a9152d8f2c5689f875182335/vignettes/desc.Rmd#L24

Hey, could you all make this data available to load from your package directly? Drop the RDA into the data folder and add descriptions into a .R script for them, and it would make replicating your vignettes much easier!

[mstackhouse]

Thanks, @thebioengineer. We can squeeze that in with the next release.