Format fix for asciidoc documentation titles.

Signed-off-by: NJunio C Hamano <junkio@cox.net>

Documentation/git-rename-script.txt

-
 git-rename-script(1)
-=====================
+====================
 v0.1, May 2005
 
 NAME

Documentation/git-repack-script.txt

 git-repack-script(1)
-=====================
+====================
 v0.99.5, August 2005
 
 NAME

Documentation/git-send-email-script.txt

 git-send-email-script(1)
-=======================
+========================
 v0.1, July 2005
 
 NAME