update Example in README.md (spf13#769)

README.md

@@ -459,7 +459,7 @@ Echo works a lot like print, except it has a child command.`,
   }
 
   var cmdTimes = &cobra.Command{
-    Use:   "times [# times] [string to echo]",
+    Use:   "times [string to echo]",
     Short: "Echo anything to the screen more times",
     Long: `echo things multiple times back to the user by providing
 a count and a string.`,