Update README file.

BUG=chromium:385712
TEST=none

Change-Id: I963243e3e8c6d3264fbcbc03f371823a9dfb9f21
Reviewed-on: https://chromium-review.googlesource.com/223350
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: Daniel Erat <derat@chromium.org>
Tested-by: Daniel Erat <derat@chromium.org>
diff --git a/README b/README
index 04d3353..01149e7 100644
--- a/README
+++ b/README
@@ -1,7 +1,6 @@
-This repository (chromiumos-assets.git) contains the unofficial, Chromium
-OS versions of assets (images, sounds, etc.) that differ between official
-and unofficial builds.  These files are installed by the
-chromeos-assets-split package.
+This repository (chromiumos-assets.git) contains the unofficial, Chromium OS
+versions of assets (images, sounds, etc.) that differ between official and
+unofficial builds. These files are installed by the chromiumos-assets package.
 
-Assets that are shared between official and unofficial builds are stored in
-assets.git and installed by the chromeos-assets package.
+See also chromeos-assets (chromeos-assets.git, official) and common-assets
+(assets.git, shared).