Merge branch 'jc/show-index-h-update'

Doc and short-help text for "show-index" has been clarified to
stress that the command reads its data from the standard input.

* jc/show-index-h-update:
  show-index: the short help should say the command reads from its input

Documentation/git-show-index.txt

@@ -9,7 +9,7 @@ git-show-index - Show packed archive index
 SYNOPSIS
 --------
 [verse]
-'git show-index' [--object-format=<hash-algorithm>]
+'git show-index' [--object-format=<hash-algorithm>] < <pack-idx-file>
 
 
 DESCRIPTION

builtin/show-index.c

@@ -9,7 +9,7 @@
 #include "parse-options.h"
 
 static const char *const show_index_usage[] = {
-	"git show-index [--object-format=<hash-algorithm>]",
+	"git show-index [--object-format=<hash-algorithm>] < <pack-idx-file>",
 	NULL
 };