open every file in a specific folder than open all of them and write "Coded by Inventex" to the first line as a comment

package main

import (
	"bufio"
	"fmt"
	"io/ioutil"
	"os"
)

func main() {
	files, err := ioutil.ReadDir("./")
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	for _, f := range files {
		if f.Name()[0] == "." {
			continue
		}
		file, _ := os.Open(f.Name())
		writer := bufio.NewWriter(file)
		writer.WriteString("// Coded by Inventex\n")
		writer.Flush()
		file.Close()
	}
}