Add a basic tutorial for the tools in depot_tools.

docs/man7/depot_tools.7

Index: docs/man7/depot_tools.7
diff --git a/docs/man7/depot_tools.7 b/docs/man7/depot_tools.7
index 7fd2128ed40bcb4b9cc627c68bbef0427ba04135..3c105e50f0beda9cebeb296e8c40903c425b04ae 100644
--- a/docs/man7/depot_tools.7
+++ b/docs/man7/depot_tools.7
@@ -1,13 +1,13 @@
 '\" t
 .\"     Title: depot_tools
 .\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
-.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/>
-.\"      Date: 03/26/2014
+.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
+.\"      Date: 04/04/2014
 .\"    Manual: Chromium depot_tools Manual
-.\"    Source: depot_tools 9c0c59f
+.\"    Source: depot_tools b4ee6b0
 .\"  Language: English
 .\"
-.TH "DEPOT_TOOLS" "7" "03/26/2014" "depot_tools 9c0c59f" "Chromium depot_tools Manual"
+.TH "DEPOT_TOOLS" "7" "04/04/2014" "depot_tools b4ee6b0" "Chromium depot_tools Manual"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -39,6 +39,8 @@ Other tools are merely \fIhelper\fR tools\&. Not required, but they can substant
 .sp
 A listing of both categories of tools follows\&.
 .SH "HELPER TOOLS"
+.sp
+A tutorial for these tools can be found at \fBdepot_tools_tutorial\fR(7)\&.
 .PP
 \fBgit-freeze\fR(1)
 .RS 4