Make usage documentation for git-add consistent.

The usage string for the executable was missing --refresh.  In
addition, the documentation referred to "file", but the usage string
referred to "filepattern".  Updated the documentation to
"filepattern", as git-add does handle patterns.
Signed-off-by: NBrian Hetro <whee@smaertness.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/git-add.txt

@@ -7,7 +7,9 @@ git-add - Add file contents to the index
 
 SYNOPSIS
 --------
-'git-add' [-n] [-v] [-f] [--interactive | -i] [-u] [--refresh] [--] <file>...
+[verse]
+'git-add' [-n] [-v] [-f] [--interactive | -i] [-u] [--refresh]
+          [--] <filepattern>...
 
 DESCRIPTION
 -----------
@@ -41,7 +43,7 @@ commit.
 
 OPTIONS
 -------
-<file>...::
+<filepattern>...::
 	Files to add content from.  Fileglobs (e.g. `*.c`) can
 	be given to add all matching files.  Also a
 	leading directory name (e.g. `dir` to add `dir/file1`

builtin-add.c

@@ -14,7 +14,7 @@
 #include "revision.h"
 
 static const char builtin_add_usage[] =
-"git-add [-n] [-v] [-f] [--interactive | -i] [-u] [--] <filepattern>...";
+"git-add [-n] [-v] [-f] [--interactive | -i] [-u] [--refresh] [--] <filepattern>...";
 
 static int take_worktree_changes;
 static const char *excludes_file;