[+] improve help prompts

Signed-off-by: Seven SUN <i@sunyz.net>

src/main.go

@@ -1,44 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"os"
-
-	"github.com/realsunyz/geofeed-tools/plugin/validate"
-)
-
-const version = "1.0.0"
-
-var help = fmt.Sprintf(
-	"Geofeed Tools Version %s (compiled to binary)\n"+
-		"Usage: ./geofeed-tools [flags] [filepath]\n\n"+
-		"Flags:\n"+
-		"  -h    Show this help message\n"+
-		"  -v    Validate a geofeed file\n", version)
-
-func main() {
-	if len(os.Args) < 2 {
-		fmt.Print(help)
-		os.Exit(1)
-	}
-
-	flag := os.Args[1]
-
-	if flag == "-h" {
-		fmt.Print(help)
-		os.Exit(1)
-	} else if flag == "-v" {
-		if len(os.Args) != 3 {
-			fmt.Println(
-				"Usage: ./geofeed-tools -v [filepath]")
-			os.Exit(1)
-		}
-		filePath := os.Args[2]
-		validate.Execute(filePath)
-	} else {
-		fmt.Printf(
-			"Error: Invalid flag \"%s\"\n"+
-				"Use \"./geofeed-tools -h\" to see available flags.\n", os.Args[1])
-		os.Exit(1)
-	}
-}