[readme-burning-isos] Adding <command> to screen text as per other examples.

[stephenw]

commit da44970a8dba9125a5ba7b3d63cf5b1f4d2a77b7
Author: Stephen Wadeley <swadeley at redhat.com>
Date:   Thu Jul 4 12:07:17 2013 +0200

    Adding <command> to screen text as per other examples.

 en-US/Validating.xml |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/en-US/Validating.xml b/en-US/Validating.xml
index a9f5f62..01bd688 100644
--- a/en-US/Validating.xml
+++ b/en-US/Validating.xml
@@ -118,8 +118,8 @@
 		<para>
 			Change into the directory that holds the ISO image files, then run <command>sha256sum</command>, for example:
 		</para>
-<screen>$ cd Downloads
-$ sha256sum Fedora-&PRODVER;-i386-DVD.iso
+    <screen>$ <command>cd Downloads</command>
+$ <command>sha256sum Fedora-&PRODVER;-i386-DVD.iso</command>
 </screen>
 		<para>
 			Open the file <filename>CHECKSUM</filename> with a text editor, such as <application>gedit</application> or <application>kwrite</application>, to display its contents. Make sure the hash displayed by <application>sha256sum</application> for <emphasis role="strong">each</emphasis> of the downloaded ISO files <emphasis role="strong">exactly</emphasis> matches the corresponding hash in the <filename>CHECKSUM</filename> file.