adkabo

I'd say, I don't think any of the directories belong in RUNTIME. config goes in CONFIG. Otherwise decide between DATA and CACHE based on the answer to "can the file...

I think we've arrived at the point where someone just needs to do it. See https://github.com/JuliaLang/julia/issues/4630#issuecomment-761265058 and https://github.com/JuliaLang/julia/issues/4630#issuecomment-761603914 for the desired directory assignments.

I wrote some code for MCMCChains + AlgebraOfGraphics a while back. https://github.com/adkabo/BayesPlots.jl/blob/main/src/plots.jl