[gnome-shell-extensions] Update README

[Giovanni Campagna <gcampagna src gnome org>]

commit 190f722fe690d7fafbbdbd0888d4e767bdce9fa8
Author: Giovanni Campagna <gcampagna src gnome org>
Date:   Thu May 12 18:59:40 2011 +0200

    Update README
    
    Add the new extensions that were left out.

 README |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/README b/README
index 0e18540..38e612d 100644
--- a/README
+++ b/README
@@ -40,6 +40,10 @@ dock
 
   Shows a dock-style task switcher on the right side of the screen.
 
+drive-menu
+  Shows a status menu for rapid unmount and power off of external storage devices
+  (i.e. pendrives)
+
 example
 
   A minimal example illustrating how to write extensions.
@@ -48,10 +52,19 @@ gajim
 
   Integration with Gajim, a Jabber/XMPP instant messaging client.
 
+native-window-placement
+
+  An alternative algorithm for layouting the thumbnails in the windows overview, that
+  more closely reflects the actual positions and sizes.
+
 places-menu
 
   Shows a status Indicator for navigating to Places.
 
+systemMonitor
+
+  An message tray indicator showing CPU and memory loads.
+
 user-theme
 
   Loads a shell theme from ~/.themes/<name>/gnome-shell.