[gparted] Add LUKS read-only / dmsetup note to the README file (#760080)

[Curtis Gedak <gedakc src gnome org>]

commit 835a5fb6d7d74c0f7c7f9a18b46dd5c885b424c7
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Sat Jan 2 14:27:17 2016 +0000

    Add LUKS read-only / dmsetup note to the README file (#760080)
    
    Bug 760080 - Implement read-only LUKS support

 README |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/README b/README
index 8c57e10..7afbadb 100644
--- a/README
+++ b/README
@@ -240,6 +240,10 @@ following command is required:
    mdadm           - SWRaid administration tool
 
 
+For LUKS read-only support the following command is required:
+   dmsetup         - Device-mapper administration tool
+
+
 For attempt data rescue for lost partitions, the following package
 is required:
    gpart           - guesses PC-type hard disk partitions