Keeping track of source code for figures #17

For editing, and then later for production, I need to keep track of where the source code is for each figure generated in the scripts under R/. I've just started adding some of these, in the form of comments:

<!-- figure-code: R/prestige.R -->

Another reason to do this is that I anticipate making many of the scripts available with the online version of the book, as I did for my categorical data analysis book, Discrete Data Analysis with R: Visualization and Modeling Techniques for Categorical and Count Data.

Is there some way to add a knitr option, fig.code =, or Quarto option fig-code: with, a chunk-hook that for now does nothing, but could be modified later to do something useful, like adding the filename to the figure caption?

```{r prestige1, fig.code = "R/prestige.R">
#| fig-code: R/prestige.R
      ...
```

Where the NULL version would look like this:

knitr::opts_knit$set(fig.source = NULL)