[patch] Documentation/email-clients.txt: add a section about git

[Dan Carpenter <dan.carpenter@oracle.com>]

These days most people don't use git to send patches so I have added a
section about that.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/Documentation/email-clients.txt b/Documentation/email-clients.txt
index 4e30eba..9004a5fd 100644
--- a/Documentation/email-clients.txt
+++ b/Documentation/email-clients.txt
@@ -1,6 +1,17 @@
 Email clients info for Linux
 ======================================================================
 
+Git
+----------------------------------------------------------------------
+These days most developers use `git send-email` instead of regular
+email clients.  On the receiving end, maintainers use `git am` to
+apply the patches.
+
+If you are new to git then send your first patch to yourself.  Save it
+as raw text including all the headers.  Run `cat raw_email.txt | git am`
+and then review the changelog with `git log -p`.  When that works then
+send the patch to list.
+
 General Preferences
 ----------------------------------------------------------------------
 Patches for the Linux kernel are submitted via email, preferably as