List common formatting errors in a Project Gutenberg candidate file

Current version

bookloupe requires the following formulae to be installed:
pkg-config 0.29.2 Manage compile and link flags for libraries
glib 2.56.1 Core application library for C

Recent formula history

Izzy Navedo Replace references to “(Mac) OS X” with “macOS”.
Dan Lowe bookloupe 2.0 (new formula)

Formula code at GitHub