Merge pull request #957 from tansaku/patch-1

indicate what running git from the terminal actually is for a newbie

Author: ben

book/01-introduction/sections/installing.asc

@@ -37,6 +37,12 @@ For more options, there are instructions for installing on several different Uni
 There are several ways to install Git on a Mac.
 The easiest is probably to install the Xcode Command Line Tools.(((Xcode)))
 On Mavericks (10.9) or above you can do this simply by trying to run 'git' from the Terminal the very first time.
+
+[source,console]
+----
+$ git --version
+----
+
 If you don't have it installed already, it will prompt you to install it.
 
 If you want a more up to date version, you can also install it via a binary installer.