Added description of the shred program.

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@611 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

appendixa/fileutils-desc.xml

@@ -165,6 +165,15 @@ rmdir removes directories, if they are empty.
 
 </sect3>
 
+<sect3><title>shred</title>
+
+<para>
+shred deletes a file securely, overwriting it first so that its contents can't
+be recovered.
+</para>
+
+</sect3>
+
 <sect3><title>sync</title>
 
 <para>