add instructions to README for using cdl.bib as a common bibliography with TeXShop/TeX Live (MacOS)

[paxtonfitzpatrick]

The common "MacTeX" TeX distribution for MacOS (which ContextLab/lab-manual links to and recommends) bundles TeX Live and some other tools, one of which is the TeXShop editor. TeXShop is generally great -- it has lots of useful features and makes working with LaTeX/BibTeX a lot easier, especially for beginners.

However, because Mac apps don't run internal commands in the user's shell environment, adding the CDL-bibliography repo to $BIBINPUTS doesn't make cdl.bib available to all projects when using TeXShop like it does if you compile from the command line.

TeX Live expects personal files to be placed in ~/Library/texmf/ and will prioritize any files there over the main texmf tree. So to make cdl.bib available to all projects:

1. create the directory BibTeX checks for personal files (it doesn't exist unless manually created)
   • mkdir -p ~/Library/texmf/bibtex/bib
2. symlink cdl.bib from your local CDL-bibliography repo into this folder
   • ln -s /Users/<username>/path/to/CDL-bibliography/cdl.bib /Users/<username>/Library/texmf/bibtex/bib/cdl.bib
   • Note: you must use absolute paths; relative paths or shortenings like ~ won't work

This method works for compiling from the command line as well, so setting $BIBINPUTS is actually not necessary. You can also place/link personal files in ~/Library/texmf/tex/latex or ~/Library/texmf/bibtex/bst/ rather than setting $BSTINPUTS or $TEXINPUTS, and this is actually the preferred/recommended method.