model extractor for LaTeX input for manual(s)

[bob-carpenter]

Use (and perhaps upgrade) the java2tex system for the manuals. That will allow naming blocks of models with comments and then pulling the relevant text out into a LaTeX-friendly file to include.

• try the java2tex system on our text
  • update if necessary
• create directory structure (or submodule structure?) to find models
• replace all the code examples in the manual with extractions from compiling models

[mitzimorris]

this would be nice to have. documentation is now in Rmd. this is possible using Rmd's "include" feature.

[mitzimorris]

if not Rmd's "include" feature, similar effect might be possible by putting example code in R code blocks which do something similar - anything that would allow us to have a directory of ".stan" files that scripts can find and check.