Emacs native compilation warning

[sdwolfz]

 ■  Warning (comp): indent-guide.el:321:2: Warning: docstring has wrong 
usage of unescaped single quotes (use \= or different quoting)

You can reproduce it by executing:

emacs -q -batch --debug-init -f batch-byte-compile indent-guide.el

Normally I would have opened a PR with the fix, similarly to how I've done for other packages, but I just can't seem to figure out how to fix this...