Documentation: Add create-ignore to git svn manual

Signed-off-by: Gustaf Hendeby <hendeby@isy.liu.se>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-svn.txt

@@ -188,6 +188,12 @@ All arguments are passed directly to `git blame'.
 	commit.  All merging is assumed to have taken place
 	independently of git-svn functions.
 
+'create-ignore'::
+
+	Recursively finds the svn:ignore property on directories and
+	creates matching .gitignore files. The resulting files are staged to
+	be committed, but are not committed.
+
 'show-ignore'::
 	Recursively finds and lists the svn:ignore property on
 	directories.  The output is suitable for appending to