Fix mis-mark-up in git-merge-file.txt documentation

Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/Documentation/git-merge-file.txt b/Documentation/git-merge-file.txt
index 0b41d66..29d3faa 100644
--- a/Documentation/git-merge-file.txt
+++ b/Documentation/git-merge-file.txt
@@ -1,9 +1,9 @@
 git-merge-file(1)
-============
+=================
 
 NAME
 ----
-git-merge-file - threeway file merge
+git-merge-file - three-way file merge
 
 
 SYNOPSIS