run "npm i"
Run "./build" in the top level directory, and look at the public directory.
A grep underline public/main.css would ideally show a line that is
specifying the underline class, but with the bug, there won't be a line
containing .underline.
Clone this (or move this) repo underneath a directory with a .gitignore file consisting entirely of * (just an asterisk).
Note that git won't pay attention to this, because this repo is a git repo, and directories above won't matter. But the tailwindcss command seems to act on this directive and ignore everything.