Add a colon cause it was bothering me :)

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@2085 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

preface/organization.xml

@@ -6,7 +6,7 @@
 book somewhat). We believe this makes for easier reading. This way, you
 don't have to keep referencing an Appendix while you read Part II. That's
 a real chore, especially if you're reading the TXT version of this book.
-This book is divided into the following parts.</para>
+This book is divided into the following parts:</para>
 
 &pf-oz-organpart1;
 &pf-oz-organpart2;