Update guix recipe

Julien LepillerWed Aug 25 00:21:45+0300 2021

449a176

gitile/assets/css
namelast commitdate
git.cssDark theme and improved markdown styleTue Aug 10 15:45:45+0300 2021
gitile.cssDark theme and improved markdown styleTue Aug 10 15:45:45+0300 2021
highlight.cssSupport shell and autoconf highlightingMon Jun 28 02:52:43+0300 2021