Put a link back to the index in every page footer

Signed-off-by: Shawn O. Pearce <sop@google.com>
diff --git a/Documentation/dev-readme.txt b/Documentation/dev-readme.txt
index 44494e7..31f4d37 100644
--- a/Documentation/dev-readme.txt
+++ b/Documentation/dev-readme.txt
@@ -152,3 +152,7 @@
 We like it.  Plus we can write Java code once and run it both in
 the browser and on the server side.  This will be very useful as
 we implement offline support in Gerrit.
+
+GERRIT
+------
+Part of link:index.html[Gerrit Code Review]