adds more descriptive usage text

.gitignore

@@ -1 +1,2 @@
-lpass.csv
+lpass.csv
+bin

build.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -e
+
+GOOS=darwin GOARCH=amd64 go build -o bin/lpass-auditor-osx
+GOOS=windows GOARCH=amd64 go build -o bin/lpass-auditor.exe
+GOOS=linux GOARCH=amd64 go build -o bin/lpass-auditor

main.go

@@ -1,16 +1,25 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
 
 	"github.com/scnewma/lpass-auditor/command"
 )
 
+func usage() {
+	fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s /path/to/csv\n", os.Args[0])
+	flag.PrintDefaults()
+}
+
 func main() {
+	flag.Usage = usage
+	flag.Parse()
+
 	command := command.Audit{}
 
-	err := command.Execute(os.Args[1:])
+	err := command.Execute(flag.Args())
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v", err)
 		os.Exit(1)