title: Golang: find string in file and show line number
body: <pre><code>read, err := ioutil.ReadFile(path)
  if err != nil {
      return err
  }
  
  if strings.Contains(string(read), "STRING") {
      // display line number?
      // what if many occurrences of the string
      // how to display for each the line number?
  }
  </code></pre>
  
  <p>I'm trying to search files for a specific string and display the line number at which the string is located.</p>