[sushi] readme: improve documentation

[Cosimo Cecchi <cosimoc src gnome org>]

commit 72874e9512106e7e428f9b791d8dccd7408dfaf0
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Thu Sep 1 18:12:48 2011 -0400

    readme: improve documentation
    
    https://bugzilla.gnome.org/show_bug.cgi?id=655379

 README |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)
---
diff --git a/README b/README
index 303043f..6028c88 100644
--- a/README
+++ b/README
@@ -1 +1,22 @@
 This is Sushi, a quick previewer for Nautilus, the GNOME desktop file manager.
+------------------------------------------------------------------------------
+
+Sushi is a DBus-activated service. For Sushi to popup, applications will have
+to call the ShowFile method on the org.gnome.NautilusPreviewer interface.
+If you want to or debug Sushi without a calling application, you can use
+gdbus(1) to call the ShowFile method manually on the bus.
+
+=======
+Methods
+=======
+
+ShowFile(s: FileUri, i: ParentXid, b: CloseIfShown)
+
+Activates Sushi previewing the file at the provided URI.
+If a XID is specified, the Sushi window is made transient to that window.
+If the CloseIfShown parameter is TRUE, Sushi will close if it's already
+running.
+
+Close()
+
+Explicitly closes Sushi.