Remove GitHub Desktop macOS section as well

Author: billygriffin

book/01-introduction/sections/installing.asc

@@ -51,10 +51,6 @@ A macOS Git installer is maintained and available for download at the Git websit
 .Git macOS Installer
 image::images/git-osx-installer.png[Git macOS installer]
 
-You can also install it as part of the GitHub for macOS install.
-Their GUI Git tool has an option to install command line tools as well.
-You can download that tool from the GitHub for macOS website, at https://desktop.github.com[].
-
 ==== Installing on Windows
 
 There are also a few ways to install Git on Windows.(((Windows, installing)))