TO DO [1/6]

[X] go through entire package and add comments, docstrings, good formatting, NOTEs and TODOs
[ ] explain how package works (use prose and diagram to show control flow)
[ ] figure out if package works well enough to refactor or if there’s a better design that needs a new package

If doing refactor:

[ ] go through pull requests and forks and merge good suggestions
[ ] standardize package prefix (probably lpp)
[ ] add let statements to make some long oneliners (e.g. with regexps) more clear

Changes so far

Added docstring and inline comments to everything in latex-preview-pane.el.