perform small update in order to bring the files up to date

Author: marrinosnis

index.asc

@@ -1,3 +1,3 @@
 [#index]
 [index]
-= Index
+== Index

progit.asc

@@ -1,13 +1,12 @@
-Pro Git
-=======
+=Pro Git
+Scott Chanon; Ben Straub
 :doctype: book
 :docinfo:
 :toc:
 :toclevels: 2
 :pagenums:
 :front-cover-image: image:book/cover.png[width=1050,height=1600]
-
-ifdef::ebook-format[:leveloffset: -1]
+:icons: font
 
 include::book/license.asc[]
 
@@ -17,7 +16,7 @@ include::book/preface_ben.asc[]
 
 include::book/dedication.asc[]
 
-//include::book/contributors.asc[]
+include::book/contributors.asc[]
 
 include::book/introduction.asc[]
 
@@ -47,4 +46,4 @@ include::B-embedding-git.asc[]
 
 include::C-git-commands.asc[]
 
-ifndef::ebook-format[include::index.asc[]]
+ifdef::backend-pdf[include::index.asc[]]