Adds introductory text about the Image service for Install Guide

Change-Id: I93c900718bcf5c5875687d4ddd3a993da3832d71

doc/common/section_getstart_image.xml

@@ -1,8 +1,8 @@
     <section xmlns="http://docbook.org/ns/docbook"
     xmlns:xi="http://www.w3.org/2001/XInclude"
     xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
-    xml:id="image-service">
+    xml:id="image-service-overview">
-      <title>Image Service</title>
+      <title>Image Service Overview</title>
       <para>The Image Service includes the following
         components:</para>
       <itemizedlist>

doc/install-guide/ch_glance.xml

@@ -4,9 +4,15 @@
     xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
     xml:id="ch_glance">
     <title>Configuring the Image Service</title>
-
+    <para>The OpenStack Image service provides users the ability to discover,
-    <para><!--FIXME: Add either intro text or a Concepts section--></para>
+        register, and retrieve virtual machine images. Also known as
-
+        the glance project, the Image service offers a REST API that
+        allows querying of virtual machine image metadata as well as
+        retrieval of the actual image. Virtual machine images made
+        available through the Image service can be stored in a variety
+        of locations from simple filesystems to object-storage systems
+        like the OpenStack Object Storage service.</para>
+    <xi:include href="../common/section_getstart_image.xml"/>
     <xi:include href="section_glance-install.xml"/>
     <xi:include href="section_glance-verify.xml"/>
 </chapter>