user-manual: use 'git config --global user.*' for setup

A simple command line call is easier than spawning an editor,
especially for folks new to ideas like the "command line" and "text
editors".  This is also the approach suggested by 'git commit' if you
try and commit without having configured user.name or user.email.
Signed-off-by: NW. Trevor King <wking@tremily.us>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/user-manual.txt

@@ -991,9 +991,16 @@ Developing with git
 Telling git your name
 ---------------------
 
-Before creating any commits, you should introduce yourself to git.  The
-easiest way to do so is to make sure the following lines appear in a
-file named .gitconfig in your home directory:
+Before creating any commits, you should introduce yourself to Git.
+The easiest way to do so is to use linkgit:git-config[1]:
+
+------------------------------------------------
+$ git config --global user.name 'Your Name Comes Here'
+$ git config --global user.email 'you@yourdomain.example.com'
+------------------------------------------------
+
+Which will add the following to a file named `.gitconfig` in your
+home directory:
 
 ------------------------------------------------
 [user]
@@ -1001,8 +1008,9 @@ file named .gitconfig in your home directory:
 	email = you@yourdomain.example.com
 ------------------------------------------------
 
-(See the "CONFIGURATION FILE" section of linkgit:git-config[1] for
-details on the configuration file.)
+See the "CONFIGURATION FILE" section of linkgit:git-config[1] for
+details on the configuration file.  The file is plain text, so you can
+also edit it with your favorite editor.
 
 
 [[creating-a-new-repository]]